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  • 1.
    Aggerstam, Thomas
    et al.
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Applied Physics, MAP.
    Pinos, Andrea
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Applied Physics, MAP.
    Marcinkevicius, Saulius
    KTH, School of Information and Communication Technology (ICT), Optics and Photonics, Optics.
    Linnarsson, Margareta
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Applied Physics, MAP.
    Lourdudoss, Sebastian
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Applied Physics, MAP.
    Electron and hole capture cross-sections of Fe acceptors in GaN:Fe epitaxially grown on sapphire2007In: Journal of Electronic Materials, ISSN 0361-5235, E-ISSN 1543-186X, Vol. 36, no 12, p. 1621-1624Article in journal (Refereed)
    Abstract [en]

    Carrier trapping of Fe (3+)/Fe2+ deep acceptors in epitaxially grown GaN:Fe on sapphire was studied by time-resolved photoluminescence. For the investigated Fe doping levels on the order of 10(18) cm(-3), the luminescence decay times are strongly dependent on the Fe concentration, indicating that Fe centers act as predominant nonradiative recombination channels. Linear dependence of the decay time on the iron concentration allows estimation of the electron capture cross-section for the Fe3+ ions, which is equal to 1.9 x 10(-15) cm(2). The upper bound for the cross-section of the hole capture of Fe2+ was evaluated as 10 x 10(-15) cm

  • 2. Barrios, C. A.
    et al.
    Messmer, E. R.
    Holmgren, M.
    Risberg, A.
    Halonen, J.
    Lourdudoss, Sebastian
    KTH, Superseded Departments, Microelectronics and Information Technology, IMIT.
    Epitaxially regrown GaAs/AlGaAs laser mesas with semi-insulating GaInP: Fe and GaAs : Fe2001In: Journal of Electronic Materials, ISSN 0361-5235, E-ISSN 1543-186X, Vol. 30, no 8, p. 987-991Article in journal (Refereed)
    Abstract [en]

    Selective regrowth of semi-insulating iron-doped Ga0.51In0.49P (SI-GaInP:Fe) and SI-GaAs:Fe around GaAs/AlGaAs mesas by hydride vapor phase epitaxy (HVPE) has been achieved. A HCl based in-situ cleaning procedure has been used to remove aluminum oxide from the etched walls of the mesas. Regrowth conducted without proper cleaning results in an irregular interface with voids. Regrowth morphology aspects are also presented. Our cleaning and regrowth methods have been used for fabricating GaAs/AlGaAs buried heterostructure in-plane lasers and vertical-cavity surface-emitting lasers.

  • 3. Battiston, S.
    et al.
    Fiameni, S.
    Saleemi, Mohsin
    KTH, School of Information and Communication Technology (ICT), Materials- and Nano Physics, Functional Materials, FNM.
    Boldrini, S.
    Famengo, A.
    Agresti, F.
    Stingaciu, M.
    Toprak, Muhammet S.
    KTH, School of Information and Communication Technology (ICT), Materials- and Nano Physics, Functional Materials, FNM.
    Fabrizio, M.
    Barison, S.
    Synthesis and Characterization of Al-Doped Mg2Si Thermoelectric Materials2013In: Journal of Electronic Materials, ISSN 0361-5235, E-ISSN 1543-186X, Vol. 42, no 7, p. 1956-1959Article in journal (Refereed)
    Abstract [en]

    Magnesium silicide (Mg2Si)-based alloys are promising candidates for thermoelectric (TE) energy conversion for the middle to high range of temperature. These materials are very attractive for TE research because of the abundance of their constituent elements in the Earth's crust. Mg2Si could replace lead-based TE materials, due to its low cost, nontoxicity, and low density. In this work, the role of aluminum doping (Mg2Si:Al = 1:x for x = 0.005, 0.01, 0.02, and 0.04 molar ratio) in dense Mg2Si materials was investigated. The synthesis process was performed by planetary milling under inert atmosphere starting from commercial Mg2Si pieces and Al powder. After ball milling, the samples were sintered by means of spark plasma sintering to density > 95%. The morphology, composition, and crystal structure of the samples were characterized by field-emission scanning electron microscopy, energy-dispersive spectroscopy, and x-ray diffraction analyses. Moreover, Seebeck coefficient analyses, as well as electrical and thermal conductivity measurements were performed for all samples up to 600A degrees C. The resultant estimated ZT values are comparable to those reported in the literature for these materials. In particular, the maximum ZT achieved was 0.50 for the x = 0.01 Al-doped sample at 600A degrees C.

  • 4. Capano, M A
    et al.
    Ryu, S
    Cooper, J A
    Melloch, M R
    Rottner, K
    Karlsson, S
    Nordell, N
    Powell, A
    Walker, D E
    Surface roughening in ion implanted 4H-silicon carbide1999In: Journal of Electronic Materials, ISSN 0361-5235, E-ISSN 1543-186X, Vol. 28, no 3, p. 214-218Article in journal (Refereed)
  • 5.
    Cheng, Jie
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Surface and Corrosion Science.
    Wang, Tongqing
    Pan, Jinshan
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Surface and Corrosion Science.
    Lu, Xinchun
    Corrosion Investigations of Ruthenium in Potassium Periodate Solutions Relevant for Chemical Mechanical Polishing2016In: Journal of Electronic Materials, ISSN 0361-5235, E-ISSN 1543-186X, Vol. 45, no 8, p. 4067-4075Article in journal (Refereed)
    Abstract [en]

    Ruthenium is the most promising material for the barrier layer used for the sub 14 nm technology node in integrated circuits manufacturing. Potassium periodate (KIO4)-based slurry is used in the chemical mechanical planarization (CMP) process of the barrier layer. However, the electrochemical and corrosion properties of ruthenium have not been investigated in such slurry. In this paper, the electrochemical and corrosion behaviors of ruthenium in KIO4 solutions were investigated under static conditions but at different pH values by potentiodynamic polarization and electrochemical impedance spectroscopy measurements, combined with surface chemical analysis using auger electron spectroscopy. Moreover, to study wear enhanced corrosion during CMP, tribocorrosion experiments were carried out to monitor the current density changes during and after mechanical scratching. The results show that at pH 6, ruthenium forms a relatively thick and heterogeneous surface film composed of RuO2 center dot 2H(2)O/RuO3, showing a high corrosion resistance and it exhibits a quick repassivation after mechanical scratching. At pH 4, ruthenium shows a passivation behavior with formation of a uniform and conductive oxide like RuO2 center dot 2H(2)O. It should be noted that there is a possible formation of RuO4 toxic gas under this condition, which should be avoided in the actual production. However, at pH 11, ruthenium exhibits no considerable passivity and the corrosion proceeds uniformly.

  • 6. Chung, S. J.
    et al.
    Shin, D. Y.
    Kim, H.
    Lee, S.
    Liu, X.
    Furdyna, J. K.
    Magneto-transport properties of a GaMnAs-based ferromagnetic semiconductor trilayer structure grown on a ZnMnSe buffer2008In: Journal of Electronic Materials, ISSN 0361-5235, E-ISSN 1543-186X, Vol. 37, no 6, p. 912-916Article in journal (Refereed)
    Abstract [en]

    Magneto-transport properties have been investigated in a ferromagnetic GaMnAs/GaAlAs/GaMnAs semiconductor trilayer structure grown on a ZnMnSe buffer layer. The presence of the ZnMnSe buffer leads to the formation of a spin-valve-like structure, which provides the opportunity to investigate spin scattering effects by Hall resistance and magnetoresistance (MR) measurements in the current-in-plane (CIP) configuration. The Curie temperature (T c) and coercivity of the bottom GaMnAs layer are observed to be different from those of the top GaMnAs layer due to the proximity effect between the ferromagnetic GaMnAs and paramagnetic ZnMnSe layers. A two-step behavior is observed in the hysteresis loops of the Hall resistance, indicating that the coercive fields are different in the two GaMnAs layers in the trilayer structure. The magnetoresistance (MR) measured simultaneously with the Hall resistance shows a sudden increase in the field region where the magnetization of the two GaMnAs layers is different. Although the MR ratio was observed to be only 0.04% in our trilayer structure (due to the experimental CIP configuration), the study clearly demonstrates the presence of spin scattering in a trilayer ferromagnetic semiconductor structure grown on a ZnMnSe buffer. © 2008 TMS.

  • 7. Danielsson, E.
    et al.
    Lee, S. K.
    Zetterling, Carl-Mikael
    KTH, Superseded Departments, Microelectronics and Information Technology, IMIT.
    Östling, Mikael
    KTH, Superseded Departments, Microelectronics and Information Technology, IMIT.
    Inductively coupled plasma etch damage in 4H-SiC investigated by Schottky diode characterization2001In: Journal of Electronic Materials, ISSN 0361-5235, E-ISSN 1543-186X, Vol. 30, no 3, p. 247-252Article in journal (Refereed)
    Abstract [en]

    Ti Schottky diodes have been used to investigate the damage caused by inductively coupled plasma (ICP) etching of silicon carbide. The Schottky diodes were characterized using TV and CV measurements. An oxidation approach was tested in order to anneal the damage, and the diode characterization was used to determine the success of the annealing. The barrier height, leakage current, and ideality factor changed significantly on the sample exposed to the etch. When the etched samples were oxidized the electrical properties were recovered and were similar to the unetched reference sample (with oxidation temperatures ranging from 900 degreesC up to 1250 degreesC). Annealing in nitrogen at 1050 degreesC did not improve the electrical characteristics. A low energy etch showed little influence on the electrical characteristics, but since the etch rate was very low the etched depth may not be sufficient in order to reach a steady state condition for the surface damage.

  • 8. Ebrahimi, P.
    et al.
    Kolahdouz, M.
    Iraj, M.
    Ganjian, M.
    Aghababa, H.
    Asl-Soleimani, E.
    Radamson, Henry H.
    KTH, School of Information and Communication Technology (ICT), Electronics, Integrated devices and circuits.
    Systematic Optimization of Boron Diffusion for Solar Cell Emitters2017In: Journal of Electronic Materials, ISSN 0361-5235, E-ISSN 1543-186X, Vol. 46, no 7, p. 4236-4241Article in journal (Refereed)
    Abstract [en]

    To achieve p-n junctions for n-type solar cells, we have studied BBr3 diffusion in an open tube furnace, varying parameters of the BBr3 diffusion process such as temperature, gas flows, and duration of individual process steps, i.e., predeposition and drive-in. Then, output parameters such as carrier lifetime, sheet resistance, and diffusion profile were measured and statistically analyzed to optimize the emitter characteristics. Statistical analysis (factorial design) was finally employed to systematically explore the effects of the set of input variables on the outputs. The effect of the interactions between inputs was also evaluated for each output, quantified using a two-level factorial method. Temperature and BBr3 flow were found to have the most significant effect on different outputs such as carrier lifetime, junction depth, sheet resistance, and final surface concentration.

  • 9.
    Ekström, Mattias
    et al.
    KTH, School of Electrical Engineering and Computer Science (EECS), Electronics.
    Ferrario, Andrea
    KTH, School of Electrical Engineering and Computer Science (EECS), Electronics.
    Zetterling, Carl-Mikael
    KTH, School of Electrical Engineering and Computer Science (EECS), Electronics.
    Investigation of a Self-Aligned Cobalt Silicide Process for Ohmic Contacts to Silicon Carbide2019In: Journal of Electronic Materials, ISSN 0361-5235, E-ISSN 1543-186X, Vol. 48, no 4, p. 2509-2516Article in journal (Refereed)
    Abstract [en]

    Previous studies showed that cobalt silicide can form ohmic contacts to p-type 6H-SiC by directly reacting cobalt with 6H-SiC. Similar results can be achieved on 4H-SiC, given the similarities between the different silicon carbide polytypes. However, previous studies using multilayer deposition of silicon/cobalt on 4H-SiC gave ohmic contacts to n-type. In this study, we investigated the cobalt silicide/4H-SiC system to answer two research questions. Can cobalt contacts be self-aligned to contact holes to 4H-SiC? Are the self-aligned contacts ohmic to n-type, p-type, both or neither? Using x-ray diffraction, it was found that a mixture of silicides (Co2Si and CoSi) was reliably formed at 800°C using rapid thermal processing. The cobalt silicide mixture becomes ohmic to epitaxially grown n-type (1×1019cm-3) if annealed at 1000°C, while it shows rectifying properties to epitaxially grown p-type (1×1019cm-3) for all tested anneal temperatures in the range 800–1000°C. The specific contact resistivity (ρC) to n-type was 4.3×10-4 Ω cm2. This work opens the possibility to investigate other self-aligned contacts to silicon carbide.

  • 10.
    Ekström, Mattias
    et al.
    KTH, School of Information and Communication Technology (ICT), Electronics.
    Khartsev, Sergiy
    KTH, School of Information and Communication Technology (ICT), Electronics.
    Östling, Mikael
    KTH, School of Information and Communication Technology (ICT), Electronics.
    Zetterling, Carl-Mikael
    KTH, School of Information and Communication Technology (ICT), Electronics.
    Integration and High-Temperature Characterization of Ferroelectric Vanadium-Doped Bismuth Titanate Thin Films on Silicon Carbide2017In: Journal of Electronic Materials, ISSN 0361-5235, E-ISSN 1543-186X, Vol. 46, no 7, p. 4478-4484Article in journal (Refereed)
    Abstract [en]

    4H-SiC electronics can operate at high temperature (HT), e.g., 300A degrees C to 500A degrees C, for extended times. Systems using sensors and amplifiers that operate at HT would benefit from microcontrollers which can also operate at HT. Microcontrollers require nonvolatile memory (NVM) for computer programs. In this work, we demonstrate the possibility of integrating ferroelectric vanadium-doped bismuth titanate (BiTV) thin films on 4H-SiC for HT memory applications, with BiTV ferroelectric capacitors providing memory functionality. Film deposition was achieved by laser ablation on Pt (111)/TiO2/4H-SiC substrates, with magnetron-sputtered Pt used as bottom electrode and thermally evaporated Au as upper contacts. Film characterization by x-ray diffraction analysis revealed predominately (117) orientation. P-E hysteresis loops measured at room temperature showed maximum 2P (r) of 48 mu C/cm(2), large enough for wide read margins. P-E loops were measurable up to 450A degrees C, with losses limiting measurements above 450A degrees C. The phase-transition temperature was determined to be about 660A degrees C from the discontinuity in dielectric permittivity, close to what is achieved for ceramics. These BiTV ferroelectric capacitors demonstrate potential for use in HT NVM applications for SiC digital electronics.

  • 11. Famengo, A.
    et al.
    Battiston, S.
    Saleemi, Mohsin
    KTH, School of Information and Communication Technology (ICT), Materials- and Nano Physics, Functional Materials, FNM.
    Boldrini, S.
    Fiameni, S.
    Agresti, F.
    Toprak, Muhammet S.
    KTH, School of Information and Communication Technology (ICT), Materials- and Nano Physics, Functional Materials, FNM.
    Barison, S.
    Fabrizio, M.
    Phase Content Influence on Thermoelectric Properties of Manganese Silicide-Based Materials for Middle-High Temperatures2013In: Journal of Electronic Materials, ISSN 0361-5235, E-ISSN 1543-186X, Vol. 42, no 7, p. 2020-2024Article in journal (Refereed)
    Abstract [en]

    The higher manganese silicides (HMS), represented by MnSi (x) (x = 1.71 to 1.75), are promising p-type leg candidates for thermoelectric energy harvesting systems in the middle-high temperature range. They are very attractive as they could replace lead-based compounds due to their nontoxicity, low-cost starting materials, and high thermal and chemical stability. Dense pellets were obtained through direct reaction between Mn and Si powders during the spark plasma sintering process. The tetragonal HMS and cubic MnSi phase amounts and the functional properties of the material such as the Seebeck coefficient and electrical and thermal conductivity were evaluated as a function of the SPS processing conditions. The morphology, composition, and crystal structure of the samples were characterized by scanning electron microscopy, energy-dispersive x-ray spectroscopy, and x-ray diffraction analyses, respectively. Differential scanning calorimetry and thermogravimetric analysis were performed to evaluate the thermal stability of the final sintered material. A ZT value of 0.34 was obtained at 600A degrees C for the sample sintered at 900A degrees C and 90 MPa with 5 min holding time.

  • 12. Fiameni, S.
    et al.
    Famengo, A.
    Agresti, F.
    Boldrini, S.
    Battiston, S.
    Saleemi, Mohsin
    KTH, School of Information and Communication Technology (ICT), Materials- and Nano Physics, Functional Materials, FNM.
    Johnsson, M.
    Toprak, Muhammet
    KTH, School of Information and Communication Technology (ICT), Materials- and Nano Physics, Functional Materials, FNM.
    Fabrizio, M.
    Effect of Synthesis and Sintering Conditions on the Thermoelectric Properties of n-Doped Mg2Si2014In: Journal of Electronic Materials, ISSN 0361-5235, E-ISSN 1543-186X, Vol. 43, no 6, p. 2301-2306Article in journal (Refereed)
    Abstract [en]

    Magnesium silicide (Mg2Si)-based alloys are promising candidates for thermoelectric (TE) energy conversion in the middle-high temperature range. The detrimental effect of the presence of MgO on the TE properties of Mg2Si based materials is widely known. For this reason, the conditions used for synthesis and sintering were optimized to limit oxygen contamination. The effect of Bi doping on the TE performance of dense Mg2Si materials was also investigated. Synthesis was performed by ball milling in an inert atmosphere starting from commercial Mg2Si powder and Bi powder. The samples were consolidated, by spark plasma sintering, to a density > 95%. The morphology, and the composition and crystal structure of samples were characterized by field-emission scanning electronic microscopy and x-ray diffraction, respectively. Moreover, determination of Seebeck coefficients and measurement of electrical and thermal conductivity were performed for all the samples. Mg2Si with 0.1 mol% Bi doping had a ZT value of 0.81, indicative of the potential of this method for fabrication of n-type bulk material with good TE performance.

  • 13. Fiameni, S.
    et al.
    Famengo, A.
    Boldrini, S.
    Battiston, S.
    Saleemi, Mohsin
    KTH, School of Information and Communication Technology (ICT), Materials- and Nano Physics, Functional Materials, FNM.
    Stingaciu, M.
    Jhonsson, M.
    Barison, S.
    Fabrizio, M.
    Introduction of Metal Oxides into Mg2Si Thermoelectric Materials by Spark Plasma Sintering2013In: Journal of Electronic Materials, ISSN 0361-5235, E-ISSN 1543-186X, Vol. 42, no 7, p. 2062-2066Article in journal (Refereed)
    Abstract [en]

    Oxide incorporation into thermoelectric Mg2Si-based materials was performed starting from commercial Mg2Si and commercial metal oxides by applying ball milling and spark plasma sintering (SPS) processing. The SPS conditions, such as sintering temperature, pressure, and holding time, were optimized with the aim of obtaining both full densification and oxide incorporation. Thermoelectric characterizations, such as Seebeck coefficient and electrical and thermal conductivity, were carried out and related to the pellet compositions. The morphology, composition, and crystallographic structure of the samples were characterized by field-emission scanning electron microscopy, energy-dispersive spectrometry, and x-ray diffraction analyses, respectively.

  • 14. Hong, J.
    et al.
    Shul, R. J.
    Zhang, L.
    Lester, L. F.
    Cho, H.
    Hahn, Y. B.
    Hays, D. C.
    Jung, K. B.
    Pearton, S. J.
    Zetterling, Carl-Mikael
    KTH, School of Information and Communication Technology (ICT), Integrated Devices and Circuits.
    Östling, Mikael
    KTH, School of Information and Communication Technology (ICT), Integrated Devices and Circuits.
    Plasma chemistries for high density plasma etching of SiC1999In: Journal of Electronic Materials, ISSN 0361-5235, E-ISSN 1543-186X, Vol. 28, no 3, p. 196-201Article in journal (Refereed)
    Abstract [en]

    A variety of different plasma chemistries, including SF6, Cl2, ICI, and IBr, have been examined for dry etching of 6H-SiC in high ion density plasma tools (inductively coupled plasma and electron cyclotron resonance). Rates up to 4500 angstroms·min-1 were obtained for SF6 plasmas, while much lower rates (≀800 angstroms·min-1) were achieved with Cl2, ICI, and IBr. The F2-based chemistries have poor selectivity for SiC over photoresist masks (typically 0.4-0.5), but Ni masks are more robust, and allow etch depths ≥10 Όm in the SiC. A micromachining process (sequential etch/deposition steps) designed for Si produces relatively low etch rates (<2,000 angstroms·min-1) for SiC.

  • 15.
    Junesand, Carl
    et al.
    KTH, School of Information and Communication Technology (ICT), Material Physics, Semiconductor Materials, HMA.
    Hu, Chen
    KTH, School of Information and Communication Technology (ICT), Material Physics, Semiconductor Materials, HMA.
    Wang, Zhechao
    KTH, School of Information and Communication Technology (ICT), Material Physics, Semiconductor Materials, HMA.
    Metaferia, Wondwosen
    KTH, School of Information and Communication Technology (ICT), Material Physics, Semiconductor Materials, HMA.
    Dagur, Pritesh
    KTH, School of Information and Communication Technology (ICT), Material Physics, Semiconductor Materials, HMA.
    Pozina, Galia
    Hultman, Lars
    Lourdudoss, Sebastian
    KTH, School of Information and Communication Technology (ICT), Material Physics, Semiconductor Materials, HMA.
    Effect of the Surface Morphology of Seed and Mask Layers on InP Grown on Si by Epitaxial Lateral Overgrowth2012In: Journal of Electronic Materials, ISSN 0361-5235, E-ISSN 1543-186X, Vol. 41, no 9, p. 2345-2349Article in journal (Refereed)
    Abstract [en]

    Heteroepitaxy of InP on Si by epitaxial lateral overgrowth (ELOG) using a thin seed layer of InP as starting material is investigated, with special attention given to the effect of the surface morphology of the seed and the mask layers on the quality of the ELOG layers. Chemical mechanical polishing (CMP) has been used to improve the morphological and optical quality of InP grown by hydride vapor-phase epitaxy (HVPE) using ELOG. Two approaches have been investigated: polishing the InP seed layer on Si before depositing the SiO2 mask and polishing the SiO2 mask after its deposition on the unprocessed seed layer. For polishing the InP (seed)/Si, a two-step process with an aluminum oxide- and sodium hypochlorite-containing slurry as well as a slurry based on sodium hypochlorite mixed with citric acid was used. For SiO2 mask polishing, a slurry with colloidal silica as an abrasive was employed. In both cases, the SiO2 mask was patterned with double line openings and ELOG carried out in an HVPE reactor. Morphology and crystal quality of the resulting ELOG layers were studied with atomic force microscopy (AFM) and room-temperature panchromatic cathodoluminescence (PC-CL) in situ in a scanning electron microscope (SEM), respectively. The results show that, whereas both polishing approaches result in an ELOG InP layer with good morphology, its surface roughness is lower when the InP (seed)/Si is subjected to CMP prior to deposition of the SiO2 mask, than when only the SiO2 mask is polished. This approach also leads to a decrease in the number of defects generated during coalescence of the ELOG layers.

  • 16. Keiper, D.
    et al.
    Westphalen, R.
    Landgren, Gunnar
    KTH, Superseded Departments, Microelectronics and Information Technology, IMIT.
    Growth of quaternary InP-based materials by LP-MOVPE using TBA and TBP in N-2 ambient2000In: Journal of Electronic Materials, ISSN 0361-5235, E-ISSN 1543-186X, Vol. 29, no 12, p. 1398-1401Article in journal (Refereed)
    Abstract [en]

    We have investigated the growth of quaternary In1-xGaxAsyP1-y/InP materials using TEA and TBP in a N-2 ambient. This process improves significantly the uniformity of In1-xGaxAs/InP QWs whereas it does not improve the quaternary Q(1.3)/InP uniformity compared to the conventional process utilizing AsH3 and PH3 in H-2. The effect on the x and y uniformity for different combinations of the group-V precursors TBA, TBP, PH3, and AsH3 with the carrier gases H-2 and N-2 is evaluated. Advantages with the TBA/TBP/N-2 process are discussed.

  • 17.
    Kim, Joo-Hyung
    et al.
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Information Technology, IMIT.
    Grishin, Alexander M.
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Information Technology, IMIT.
    Ignatova, Velislava Angelova
    Fraunhofer Institute, Center of Nanoelectronic Technologies (CNT).
    Wet etching study of La-0.67(Sr0.5Ca0.5)(0.33)MnO3 films on silicon substrates2008In: Journal of Electronic Materials, ISSN 0361-5235, E-ISSN 1543-186X, Vol. 37, no 3, p. 361-367Article in journal (Refereed)
    Abstract [en]

    Wet etching of colossal magnetoresistive (CMR) perovskite La-0.67(Sr0.5Ca0.5)(0.33)MnO3 (LSCMO) films on Bi4Ti3O12/CeO2/yttrium-stabilized zirconia (YSZ)-buffered Si substrates was investigated using potassium hydroxide (KOH) and buffered hydrofluoric acid (BHF) solutions. X-ray diffraction (XRD) and scanning spreading resistance microscopy (SSRM) measurements revealed that the morphological roughness of the LSCMO films increases, while the electrical resistance roughness decreases, with increasing KOH etching time. The LSCMO films are highly chemically resistant to KOH solution; however, in the case of BHF etching, an etch rate of 22 nm/min was obtained with high selectivity over a photoresist mask.

  • 18. Konstantinov, A O
    et al.
    Wahab, Q
    Nordell, N
    Lindefelt, U
    Study of avalanche breakdown and impact ionization in 4H silicon carbide1998In: Journal of Electronic Materials, ISSN 0361-5235, E-ISSN 1543-186X, Vol. 27, no 4, p. 335-341Article in journal (Refereed)
  • 19. Lee, S. K.
    et al.
    Koo, S. M.
    Zetterling, Carl-Mikael
    KTH, Superseded Departments, Microelectronics and Information Technology, IMIT.
    Östling, Mikael
    KTH, Superseded Departments, Microelectronics and Information Technology, IMIT.
    Ohmic contact formation on inductively coupled plasma etched 4H-silicon carbide2002In: Journal of Electronic Materials, ISSN 0361-5235, E-ISSN 1543-186X, Vol. 31, no 5, p. 340-345Article in journal (Refereed)
    Abstract [en]

    We report on the investigation of ohmic contact formation using sputtered titanium-tungsten contacts on an inductively coupled plasma (ICP) etch-damaged 4H-SiC surface. Transfer length method (TLM) measurements were performed to characterize how ICP-etch damage affects the performance of ohmic contacts to silicon carbide. In order to recover etch damage, high-temperature oxidation (1250degreesC for 1 h) was evaluated for one of the samples. Some of the etch damage was recovered, but it did not fully recover the etch damage for the sample etched with medium platen power (60 W). From our TLM measurements, the specific contact resistance (rho(C) of sputtered titanium tungsten on highly doped n(+)-type 4H-SiC epilayers with a doping of 1.1 X 10(19) cm(-3) for the unetched reference sample, 30-W etched, and 60-W etched with and without sacrificial oxidation was as low as 3.8 X 10(-5) Omegacm(2), 3.3 X 10(-5) Omega cm(2), 2.3 X 10(-4) Omegacm(2), and 1.3 X 10(-3) Omegacm(2), respectively. We found that the low-power (30 W) ICP-etching process did not affect the formation of ohmic contacts, and we did not observe any difference between the unetched and the 30-W etched sample from our TLM measurements, having the same value of the rho(C). However, medium-platen-power (60 W) ICP etching showed significant influence on the ohmic contact formation. We found that the specific contact resistance is highly related to the surface roughness and quality of the metals, and the lower, specific contact resistance is due to the smoother and denser ohmic contacts.

  • 20. Lee, S. K.
    et al.
    Zetterling, Carl-Mikael
    KTH, Superseded Departments, Microelectronics and Information Technology, IMIT.
    Östling, Mikael
    KTH, Superseded Departments, Microelectronics and Information Technology, IMIT.
    Schottky barrier height dependence on the metal work function for p-type 4H-silicon carbide2001In: Journal of Electronic Materials, ISSN 0361-5235, E-ISSN 1543-186X, Vol. 30, no 3, p. 242-246Article in journal (Refereed)
    Abstract [en]

    We investigated Schottky barrier diodes of several metals (Ti, Ni, and Au) having different metal work functions to p-type 4H-SiC (0001) using I-V and C-V characteristics. Contacts showed excellent Schottky behavior with stable ideality factors of 1.07, 1.23, and 1.06 for Ti, Ni, and Au, respectively, in the range of 24 degreesC to 300 degreesC. The measured Schottky barrier height (SBH) was 1.96, 1.41, and 1.42 eV for Ti, Ni, and Au, respectively, in the same temperature range from IV characteristics. Based on our measurements for p-type 4H-SiC, the SBH (phi (Bp)) and metal work functions (phi (m)) show a linear relationship of phi (Bp) = 4.58 - 0.61 phi (m) and phi (Bp) = 4.42 - 0.54(phim) for I-V and C-V characteristics at room temperature, respectively. We observed that the SBH strongly depends on the metal work function with a slope (S = phi (Bp)/phi (m)) of 0.58 even though the Fermi level is partially pinned. We found the sum of the SBH (phi (Bp) + phi (Bn) = E-g) at room temperature for nand p-type 4H-SiC to be 3.07 eV, 3.12 eV, and 3.21 eV for Ti, Ni, and Au, respectively, using I-V and C-V measurements, which are in reasonable accord with the Schottky-Mott limit.

  • 21. Leerungnawarat, P.
    et al.
    Cho, H.
    Pearton, S. J.
    Zetterling, Carl-Mikael
    KTH, Superseded Departments, Microelectronics and Information Technology, IMIT.
    Östling, Mikael
    KTH, Superseded Departments, Microelectronics and Information Technology, IMIT.
    Effect of UV light irradiation on SiC dry etch rates2000In: Journal of Electronic Materials, ISSN 0361-5235, E-ISSN 1543-186X, Vol. 29, no 3, p. 342-346Article in journal (Refereed)
    Abstract [en]

    Inductively Coupled Plasma etching of 4H-SiC under ultraviolet illumination was examined for SF6/Ar and Cl-2/Ar chemistries. Etch rate enhancements up to a factor of 8 were observed with UV light irradiation during Cl-2/Ar etching. The enhancement mechanism is related to photodesorption of SiClx and CClx species. Surface morphologies were unchanged as a result of the UV enhancement with Cl-2/Ar discharges. By contrast, there was no effect of UV irradiation on the SiC etch rates in SF6/Ar plasmas, but the surfaces were typically smoother than those obtained without the ultraviolet illumination. In the SF6/Ar chemistry the rate-limiting steps are either Si-C bond-breaking or supply of fluorine radicals to the surface, and not desorption of the SiFx and CFx etch products.

  • 22.
    Li, Molan
    et al.
    KTH, School of Information and Communication Technology (ICT), Electronic Systems.
    Xu, Shaohui
    KTH, School of Information and Communication Technology (ICT), Electronic Systems.
    Chen, Qiang
    KTH, School of Information and Communication Technology (ICT), Electronic Systems.
    Zheng, Li-Rong
    KTH, School of Information and Communication Technology (ICT), Electronic Systems.
    Thermoelectric-Generator-Based DC-DC Conversion Networks for Automotive Applications2011In: Journal of Electronic Materials, ISSN 0361-5235, E-ISSN 1543-186X, Vol. 40, no 5, p. 1136-1143Article in journal (Refereed)
    Abstract [en]

    Maximizing electrical energy generation through waste heat recovery is one of the modern research questions within automotive applications of thermoelectric (TE) technologies. This paper proposes a novel concept of distributed multisection multilevel DC-DC conversion networks based on thermoelectric generators (TEGs) for automotive applications. The concept incorporates a bottom-up design approach to collect, convert, and manage vehicle waste heat efficiently. Several state-of-the-art thermoelectric materials are analyzed for the purpose of power generation at each waste heat harvesting location on a vehicle. Optimal materials and TE couple configurations are suggested. Moreover, a comparison of prevailing DC-DC conversion techniques was made with respect to applications at each conversion level within the network. Furthermore, higher-level design considerations are discussed according to system specifications. Finally, a case study is performed to compare the performance of the proposed network and a traditional single-stage system. The results show that the proposed network enhances the system conversion efficiency by up to 400%.

  • 23.
    Lourdudoss, Sebastian
    et al.
    KTH, Superseded Departments, Microelectronics and Information Technology, IMIT.
    Hammarlund, Bo
    KTH, Superseded Departments, Microelectronics and Information Technology, IMIT.
    Kjebon, Olle
    KTH, Superseded Departments, Microelectronics and Information Technology, IMIT.
    An investigation on hydride VPE growth and properties of semi-insulating InP:Fe1990In: Journal of Electronic Materials, ISSN 0361-5235, E-ISSN 1543-186X, Vol. 19, no 9, p. 981-987Article in journal (Refereed)
    Abstract [en]

    Growth of highly resistive semi-insulating InP : Fe has been achieved by the Hydride VPE technique in an ambient consisting mostly of nitrogen. After dealing with some thermodynamic considerations pertinent to InP:Fe growth, the experimental growth parameters are described. It is shown that various amounts of iron can be introduced into the InP crystal just by varying the temperature of the iron source. The crystal quality of the grown material is estimated to be good by etch pit density and x-ray diffraction analyses. Current-voltage behaviour and capacitance studies on an n+-SI-n+ structure are explained by invoking the theory of current injection in solids by Lampert and Mark: the experimental current densities at the threshold of each observed regime are compared with the theoretically derived current densities; in the absence of current injection, the measured capacitance is found to be the same as the geometrical capacitance.

  • 24.
    Lourdudoss, Sebastian
    et al.
    KTH, Superseded Departments, Electronics.
    Rodríguez Messmer, E.
    KTH, Superseded Departments, Electronics.
    Kjebon, Olle
    KTH, Superseded Departments, Electronics.
    Landgren, Gunnar
    KTH, Superseded Departments, Electronics.
    Temporally resolved selective regrowth of InP around [110] and [110] mesas1996In: Journal of Electronic Materials, ISSN 0361-5235, E-ISSN 1543-186X, Vol. 25, no 3, p. 389-394Article in journal (Refereed)
    Abstract [en]

    Temporally resolved selective regrowth of InP around reactive ion etched [110] and [110] directional mesas is studied by hydride vapor phase epitaxy at the growth temperatures of 600, 650, 685, and 700°C. The regrowth profiles are strikingly different depending upon the mesa orientation. The results are interpreted by invoking the difference in the bonding configurations of these mesas as well as the growth facility in a direction leading to the largest reduction of dangling bonds under the growth conditions. Various emerging planes during regrowth are identified and are {hhl} planes with initial values of l/h ≤ 3 but ≥ 3 as the planarization is approached. Initial lateral growth defined as the growth away from the mesa at half of its height in the very first minute is a decreasing function of temperature when plotted as Arrhenius curves. Such a behavior is attributed to the exothermicity of the reaction and to an enhanced pyrolysis of PH3 to P2. The lateral growth rate is much larger than that on the planar substrate. This should be taken into account when regrowth of a doped layer (e.g. InP:Fe or InP:Zn) is carried out to fabricate a buried heterostructure device since the dopant concentration can be very much lower than the one optimized on the planar substrates.

  • 25. Lundberg, N.
    et al.
    Östling, Mikael
    KTH, Superseded Departments, Microelectronics and Information Technology, IMIT.
    Zetterling, Carl-Mikael
    KTH, Superseded Departments, Microelectronics and Information Technology, IMIT.
    Tagtstrom, P.
    Jansson, U.
    CVD-based tungsten carbide Schottky contacts to 6H-SiC for very high-temperature operation2000In: Journal of Electronic Materials, ISSN 0361-5235, E-ISSN 1543-186X, Vol. 29, no 3, p. 372-375Article in journal (Refereed)
    Abstract [en]

    In this study, tungsten carbide, with its hardness, chemical inertness, thermal stability and low resistivity (25 mu Omega cm)(1) is shown as a reliable contact material to n- and p-type 6H-SiC for very high temperature applications. WC films with thicknesses of 100-150 nm were deposited by chemical vapor deposition (CVD) from a WF6/C3H8/H-2 mixture at 1173 K. A method to pattern CVD-tungsten carbide is suggested. TEM analysis of as deposited samples displayed a clear and unreacted interface. The electrical investigations of the p-type 6H-SiC Schottky contacts revealed a high rectification ratio and a low reverse current density (6.1 x 10(-5) A cm(-2), -10 V) up to 713 K. On n-type, a low barrier (Phi(Bn) = 0.79 eV) at room temperature was observed. The low Phi(Bn) value suggests WC to be promising as an ohmic contact material on highly doped n-type epi-layers. We will show a temperature dependence for the barrier height of tungsten carbide contacts that can be related to the simultaneous change in the energy bandgap, which should be considered when designing SiC devices intended for high temperature operation.

  • 26.
    Mirsakiyeva, Amina
    et al.
    KTH, School of Information and Communication Technology (ICT), Materials- and Nano Physics.
    Hugosson, Håkan W.
    KTH, School of Information and Communication Technology (ICT), Materials- and Nano Physics. Univ Gävle, Sweden.
    Crispin, Xavier
    Delin, Anna
    KTH, School of Information and Communication Technology (ICT), Materials- and Nano Physics. KTH, Centres, SeRC - Swedish e-Science Research Centre. Uppsala Univ, Sweden.
    Quantum Molecular Dynamical Calculations of PEDOT 12-Oligomer and its Selenium and Tellurium Derivatives2017In: Journal of Electronic Materials, ISSN 0361-5235, E-ISSN 1543-186X, Vol. 46, no 5, p. 3071-3075Article in journal (Refereed)
    Abstract [en]

    We present simulation results, computed with the Car-Parrinello molecular dynamics method, at zero and ambient temperature (300 K) for poly(3,4-ethylenedioxythiophene) [PEDOT] and its selenium and tellurium derivatives PEDOS and PEDOTe, represented as 12-oligomer chains. In particular, we focus on structural parameters such as the dihedral rotation angle distribution, as well as how the charge distribution is affected by temperature. We find that for PEDOT, the dihedral angle distribution shows two distinct local maxima whereas for PEDOS and PEDOTe, the distributions only have one clear maximum. The twisting stiffness at ambient temperature appears to be larger the lighter the heteroatom (S, Se, Te) is, in contrast to the case at 0 K. As regards point charge distributions, they suggest that aromaticity increases with temperature, and also that aromaticity becomes more pronounced the lighter the heteroatom is, both at 0 K and ambient temperature. Our results agree well with previous results, where available. The bond lengths are consistent with substantial aromatic character both at 0 K and at ambient temperature. Our calculations also reproduce the expected trend of diminishing gap between the highest occupied molecular orbital and the lowest unoccupied molecular orbital with increasing atomic number of the heteroatom.

  • 27.
    Nguyen, T. N. Anh
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Fedotova, J.
    Belarusian State Univ, Inst Nucl Problems, Minsk 220030, BELARUS.;AGH Univ Sci & Technol, Fac Phys & Appl Comp Sci, PL-30059 Krakow, Poland..
    Kasiuk, J.
    Belarusian State Univ, Inst Nucl Problems, Minsk 220030, BELARUS..
    Wu, W. -B
    Przewoznik, J.
    AGH Univ Sci & Technol, Fac Phys & Appl Comp Sci, PL-30059 Krakow, Poland..
    Kapusta, C.
    AGH Univ Sci & Technol, Fac Phys & Appl Comp Sci, PL-30059 Krakow, Poland..
    Kupreeva, O.
    Belarusian State Univ Informat & Radioelect, Minsk 220013, BELARUS..
    Lazarouk, S.
    Belarusian State Univ Informat & Radioelect, Minsk 220013, BELARUS..
    Trinh, T. H. Thuy
    Vietnam Acad Sci & Technol, Inst Mat Sci, Hanoi, Vietnam..
    Do, K. Tung
    Vietnam Acad Sci & Technol, Inst Mat Sci, Hanoi, Vietnam..
    Do, H. Manh
    Vietnam Acad Sci & Technol, Inst Mat Sci, Hanoi, Vietnam..
    Vu, D. Lam
    Vietnam Acad Sci & Technol, Inst Mat Sci, Hanoi, Vietnam..
    Åkerman, Johan
    KTH, School of Engineering Sciences (SCI), Applied Physics, Materials and Nanophysics. Royal Inst Technol, Mat Phys Dept, S-16440 Kista, Sweden..
    Enhanced Perpendicular Exchange Bias in Co/Pd Antidot Arrays2019In: Journal of Electronic Materials, ISSN 0361-5235, E-ISSN 1543-186X, Vol. 48, no 3, p. 1492-1497Article in journal (Refereed)
    Abstract [en]

    Magnetic nanostructures revealing the exchange bias (EB) effect have attracted much interest in recent years due to their promising applications in spintronics, magneticsensing and recording devices with various functionalities. In this paper, we report on the perpendicular exchange bias effect in a multilayered thin film composed of [Co/Pd] ferromagnetic multilayers exchange-coupled to an antiferromagnetic IrMn. The film was deposited on a porous anodized titania template. Influences of the films' surface morphology as well as the order of layers deposited on the EB effect were studied. The enhancements of the EB field H-EB (up to 30%) and the coercive field H-C (two times) were achieved in the nanoporous films relative to their continuous film counterparts, which could be attributed to the specific morphology of the porous surfaces.

  • 28. Nordell, N.
    et al.
    Schöner, A.
    Linnarsson, Margareta K.
    KTH, Superseded Departments, Electronics.
    Control of Al and B doping transients in 6H and 4H SiC grown by vapor phase epitaxy1997In: Journal of Electronic Materials, ISSN 0361-5235, E-ISSN 1543-186X, Vol. 26, no 3, p. 187-192Article in journal (Refereed)
    Abstract [en]

    The atomic concentration profiles in 4H and 6H SiC created by Al and B doping turn-on and turn-off during vapor phase epitaxy (VPE) was investigated by secondary ion mass spectrometry (SIMS). It was found that dopant traces were adsorbed to the reactor walls and re-evaporated after the dopant precursor flow was switched off. This adsorption/re-evaporation process limits the doping dynamic range to about three orders of magnitude for Al, and two orders of magnitude for B. An order of magnitude in doping dynamics could be gained by simultaneously switching the gases and changing the C:Si precursor ratio. By adding a 10 min growth interruption with an H or HC1 etch at the doping turn-off, the background doping tail could be considerably suppressed. In total, a doping dynamics for Al of almost five orders of magnitude can be controlled within a 30 nm layer. For B, the dynamic range is more than three orders of magnitude, and the abruptness is most probably diffusion limited. Abackground doping level of 2 × 1015 cm−3 for Al and 2 × 1016 cm−3 for B was obtained. For Al, the background doping is most probably due to the adsorption/re-evaporation of dopants at the reactor walls; while for B, the background doping may in addition be limited by diffusion.

  • 29.
    Nordell, Nils
    et al.
    KTH.
    Schoner, A.
    Rottner, K.
    Persson, P. O. A.
    Wahab, Q.
    Hultman, L.
    Linnarsson, Margareta
    KTH.
    Olsson, E.
    Boron implantation and epitaxial regrowth studies of 6H SiC1998In: Journal of Electronic Materials, ISSN 0361-5235, E-ISSN 1543-186X, Vol. 27, no 7, p. 833-837Article in journal (Refereed)
    Abstract [en]

    Implantation of B has been performed into an epitaxially grown layer of 6H SiC, at two different B concentrations, 2 x 10(16) cm(-3) and 2 x 10(18) cm(-3). Subsequently, an epitaxial layer was regrown on the B implanted layer. The samples were investigated by transmission electron microscopy (TEM) and secondary ion mass spectrometry (SIMS). In the highly B-doped layers plate-like defects were found, associated with large strain fields, and an increased B concentration. These defects were stable at the originally implanted region during regrowth and at anneal temperatures up to 1700 degrees C. In the samples implanted with the lower B concentration, no crystal defects could be detected by TEM. No threading dislocations or other defects were observed in the regrown epitaxial layer, which shows the possibility to grow a layer with high crystalline quality on B implanted 6H SiC. By SIMS, it was found that B piles up at the interface to the regrown layer, which could be explained by enhanced diffusion from an increased concentration of point defects created by implantation damage in the region. B is also spread out into the original crystal and in the regrown layer at a concentration of below 2 x 10(16) cm(-3), with a diffusion constant estimated to 1.3 x 10(-12) cm(2)s(-1). This diffusion is most probably not driven by implantation damage, but by intrinsic defects in the grown crystal. Our investigation shows that the combination of implantation and subsequent regrowth techniques could be used in SiC for building advanced device structures, with the crystal quality in the regrown layer not being deteriorated by crystal defects in the implanted region. A device process using B implantation and subsequent regrowth could on the other hand be limited by the diffusion of B.

  • 30. Saleemi, Mohsin
    et al.
    Ruditskiy, A.
    Toprak, Muhammet
    KTH, School of Information and Communication Technology (ICT), Materials- and Nano Physics, Functional Materials, FNM.
    Stingaciu, M.
    Johnsson, M.
    Kretzschmar, I.
    Jacquot, A.
    Jaegle, M.
    Muhammed, Mamoun
    KTH, School of Information and Communication Technology (ICT), Materials- and Nano Physics, Functional Materials, FNM.
    Evaluation of the Structure and Transport Properties of Nanostructured Antimony Telluride (Sb2Te3)2014In: Journal of Electronic Materials, ISSN 0361-5235, E-ISSN 1543-186X, Vol. 43, no 6, p. 1927-1932Article in journal (Refereed)
    Abstract [en]

    Antimony telluride, (Sb2Te3), and its doped derivatives are considered to be among the best p-type thermoelectric (TE) materials for room temperature (300-400 K) applications. However, it is still desirable to develop rapid and economical routes for large-scale synthesis of Sb2Te3 nanostructures. We report herein a high yield, simple and easily scalable synthetic method for polycrystalline Sb2Te3 nanostructures. Prepared samples were compacted into dense pellets by use of spark plasma sintering. The products were characterized by x-ray diffraction and scanning electron microscopy. To investigate the anisotropic behavior of Sb2Te3 TE transport property measurements were performed along and perpendicular to the direction of compaction. Thermal conductivity, electrical conductivity, and Seebeck coefficient measurement over the temperature range 350-525 K showed that the anisotropy of the material had a large effect on TE performance.

  • 31. Soderstrom, D.
    et al.
    Lourdudoss, Sebastian
    KTH, Superseded Departments, Microelectronics and Information Technology, IMIT.
    Dadgar, A.
    Stenzel, O.
    Bimberg, D.
    Schumann, H.
    Dopant diffusion and current-voltage studies on epitaxial InP codoped with Ru and Fe2001In: Journal of Electronic Materials, ISSN 0361-5235, E-ISSN 1543-186X, Vol. 30, no 8, p. 972-976Article in journal (Refereed)
    Abstract [en]

    Semi-insulating Fe and Ru codoped InP epitaxial layers grown by low-pressure hydride vapor phase epitaxy have been investigated. InP:Ru and InP:Fe,Ru layers were grown on p-InP:Zn and n-InP:S substrates, in order to study dopant diffusion and electrical characteristics. Dopant diffusion profiles of Ru, Fe and Zn were measured by secondary ion mass spectroscopy. A small but noteworthy diffusion front is observed when InP:Ru is adjacent to InP:Zn, but not when adjacent to n-InP. For InP:Fe codoped with Ru a pronounced interdiffusion of Fe and Zn is observed for Ru concentrations less than 2 X 10(17) cm(-3), but, for a higher Ru concentration the interdiffusion is clearly suppressed. Moreover, when InP is codoped with Fe and Ru, the small diffusion tail of Ru in InP:Zn vanishes. Unlike InP:Fe, resistivities above 1 X 10(8) Ohm cm are measured for both electron and hole-current injection in InP:Fe,Ru.

  • 32.
    Wang, Wei
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment, Geoinformatics.
    Yang, Lili
    Wang, Nan
    Zhang, Haifeng
    Jia, Yanping
    Design of a Thermoelectric Material Using the CALPHAD Technique: Thermodynamic Reassessment of the Al-Sb-Zn System2018In: Journal of Electronic Materials, ISSN 0361-5235, E-ISSN 1543-186X, Vol. 47, no 1, p. 261-271Article in journal (Refereed)
    Abstract [en]

    The beta-Sb3Zn4 intermetallic compound, one of the most promising thermoelectric materials in the mid-1990s, has attracted much interest due to its high thermoelectric performance in the intermediate temperature range. To improve the thermoelectric properties of the compound beta-Sb3Zn4, Al doping is an effective method. Therefore, accurate theoretical analysis of the Al-Sb-Zn system is essential for the design of such thermoelectric materials. In this work, the Al-Sb-Zn system was reassessed by means of the calculation of phase diagram (CALPHAD) technique. A set of self-consistent thermodynamic parameters was obtained and can be used to extrapolate to related high-order systems. Some phase equilibria and thermochemical properties can be predicted using the present thermodynamic description.

  • 33. Xu, Shaohui
    et al.
    Chen, Qiang
    KTH, School of Information and Communication Technology (ICT), Electronic Systems.
    Zhu, Yiping
    Wang, Lianwei
    Zheng, Lirong
    KTH, School of Information and Communication Technology (ICT), Electronic Systems.
    Chu, Paul K.
    Modeling and Optimization of Thermoelements by a Combined Analytical and Numerical Method2014In: Journal of Electronic Materials, ISSN 0361-5235, E-ISSN 1543-186X, Vol. 43, no 2, p. 404-413Article in journal (Refereed)
    Abstract [en]

    A combined analytical and numerical process has been developed to model and optimize thermoelements. In this way, the performance of commercial n- and p-type thermoelectric materials can be optimized to deliver the maximum output power and conversion efficiency. The validity of the method is demonstrated using a silicon germanium unicouple.

1 - 33 of 33
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