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Khartsev, S., Sarakovskis, A., Grinberga, L., Hammar, M., Nordell, N. & Hallén, A. (2024). Electrical and Optical Properties of a Cu2O/β-Ga2O3 pn-Junction. Physica Status Solidi (A): Applications and Materials Science, 221(10), Article ID 2300958.
Open this publication in new window or tab >>Electrical and Optical Properties of a Cu2O/β-Ga2O3 pn-Junction
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2024 (English)In: Physica Status Solidi (A): Applications and Materials Science, ISSN 1862-6300, E-ISSN 1862-6319, Vol. 221, no 10, article id 2300958Article in journal (Refereed) Published
Abstract [en]

A pn-heterojunction is fabricated by depositing an n-type β-Ga2O3 film by pulsed laser deposition (PLD) on c-cut Al2O3. P-type cuprous oxide films, Cu2O, are then deposited by PLD, as well as by radio frequency (RF) magnetron sputtering. It is concluded that hole injection is prohibited by a 3.26 eV valence band barrier, as measured by X-ray photo-electron spectroscopy (XPS) and ultraviolet photoelectron spectroscopy (UPS). Heterojunction diode structures are prepared on the front side and electrical measurements demonstrate a rectification ration of 8 orders of magnitude and an ideality factor close to 2, indicating interface recombination-controlled forward current. The junction is also optically active and shows a very fast photo-response to 275 nm UV light. 

Place, publisher, year, edition, pages
Wiley, 2024
Keywords
electro-optical properties, magnetron sputtering, pulsed laser deposition, semiconducting oxides, transparent conducting oxide, UV photodetector
National Category
Condensed Matter Physics
Identifiers
urn:nbn:se:kth:diva-366900 (URN)10.1002/pssa.202300958 (DOI)001194738800001 ()2-s2.0-85189105203 (Scopus ID)
Note

QC 20250711

Available from: 2025-07-11 Created: 2025-07-11 Last updated: 2025-07-11Bibliographically approved
Khartsev, S., Hammar, M., Nordell, N., Zolotarjovs, A., Purans, J. & Hallén, A. (2021). Reverse‐Bias Electroluminescence in Er‐Doped β‐Ga 2 O 3 Schottky Barrier Diodes Manufactured by Pulsed Laser Deposition. Physica Status Solidi (a) applications and materials science, 219(4), 2100610-2100610
Open this publication in new window or tab >>Reverse‐Bias Electroluminescence in Er‐Doped β‐Ga 2 O 3 Schottky Barrier Diodes Manufactured by Pulsed Laser Deposition
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2021 (English)In: Physica Status Solidi (a) applications and materials science, ISSN 1862-6300, E-ISSN 1862-6319, Vol. 219, no 4, p. 2100610-2100610Article in journal (Refereed) Published
Place, publisher, year, edition, pages
Wiley, 2021
National Category
Condensed Matter Physics
Identifiers
urn:nbn:se:kth:diva-312751 (URN)10.1002/pssa.202100610 (DOI)000736523700001 ()2-s2.0-85122124368 (Scopus ID)
Note

QC 20220621

Available from: 2022-05-23 Created: 2022-05-23 Last updated: 2022-06-25Bibliographically approved
Khartsev, S., Nordell, N., Hammar, M., Purans, J. & Hallén, A. (2020). High‐Quality Si‐Doped β‐Ga 2 O 3 Films on Sapphire Fabricated by Pulsed Laser Deposition. Physica status solidi. B, Basic research, 258(2), 2000362-2000362
Open this publication in new window or tab >>High‐Quality Si‐Doped β‐Ga 2 O 3 Films on Sapphire Fabricated by Pulsed Laser Deposition
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2020 (English)In: Physica status solidi. B, Basic research, ISSN 0370-1972, E-ISSN 1521-3951, Vol. 258, no 2, p. 2000362-2000362Article in journal (Refereed) Published
Abstract [en]

Pulsed laser ablation is used to form high-quality silicon-doped β-Ga2O3 films on sapphire by alternatively depositing Ga2O3 and Si from two separate sources. X-ray analysis reveals a single crystallinity with a full width at half maximum for the rocking curve around the (−201) reflection peak of 1.6°. Silicon doping concentration is determined by elastic recoil detection analysis (ERDA), and the best electrical performance is reached at a Si concentration of about 1 × 1020 cm−3, using optimized deposition parameters. It is found that a high crystalline quality and a mobility of about 2.9 cm2 (V s)−1 can be achieved by depositing Si and Ga2O3 from two separate sources. Two types of Schottky contacts are fabricated: one with a pure Pt and one with a PtOx composition. Electrical results from these structures are also presented. 

Place, publisher, year, edition, pages
Wiley, 2020
National Category
Condensed Matter Physics
Identifiers
urn:nbn:se:kth:diva-312752 (URN)10.1002/pssb.202000362 (DOI)000572073100001 ()2-s2.0-85091360303 (Scopus ID)
Note

QC 20220621

Available from: 2022-05-23 Created: 2022-05-23 Last updated: 2022-06-25Bibliographically approved
Linnarsson, M. K., Janson, M. S., Nordell, N., Wong-Leung, J. & Schoner, A. (2006). Formation of precipitates in heavily boron doped 4H-SiC. Applied Surface Science, 252(15), 5316-5320
Open this publication in new window or tab >>Formation of precipitates in heavily boron doped 4H-SiC
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2006 (English)In: Applied Surface Science, ISSN 0169-4332, E-ISSN 1873-5584, Vol. 252, no 15, p. 5316-5320Article in journal (Refereed) Published
Abstract [en]

Secondary ion mass spectrometry (SIMS) and transmission electron microscopy (TEM) are utilized to study precipitation and the solubility of B in 4H-SiC epitaxial layers super saturated with B. Heat treatments are performed in Ar atmosphere in an rf-heated furnace at temperatures between 1700 and 2000 degrees C. SIMS ion images, and TEM micrographs reveal the formation of two types of precipitates where the larger, more thermally stable one is suggested to be B4C. The boron solubility is determined from SIMS depth profiles and is shown to follow the Arrhenius expression: 7.1 x 10(22) exp(-1.4 eV/k(B)T) cm(-3) over the studied temperature range.

Keywords
SIMS, TEM, SiC, B, solubility limit, precipitates, silicon-carbide, diffusion, epitaxy
National Category
Materials Engineering Materials Chemistry
Identifiers
urn:nbn:se:kth:diva-15785 (URN)10.1016/j.apsusc.2005.12.024 (DOI)000238623300019 ()2-s2.0-33744532107 (Scopus ID)
Note

QC 20100525 QC 20111004. QC 20150626,  Conference: 8th International Conference on Atomically Controlled Surfaces, Interfaces, and Nanostructures/13th International Congress on Thin Films. Stockholm, SWEDEN. JUN 20-23, 2005

Available from: 2010-08-05 Created: 2010-08-05 Last updated: 2022-06-25Bibliographically approved
Nordell, N., Bowallius, O., Anand, S., Kakanakova-Georgieva, A., Yakimova, R., Madsen, L. D., . . . Konstantinov, A. O. (2002). Polytype homogeneity and doping distribution in homoepitaxial 4H SiC grown on nonplanar substrates. Applied Physics Letters, 80(10), 1755-1757
Open this publication in new window or tab >>Polytype homogeneity and doping distribution in homoepitaxial 4H SiC grown on nonplanar substrates
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2002 (English)In: Applied Physics Letters, ISSN 0003-6951, E-ISSN 1077-3118, Vol. 80, no 10, p. 1755-1757Article in journal (Refereed) Published
National Category
Natural Sciences
Identifiers
urn:nbn:se:kth:diva-161274 (URN)10.1063/1.1458048 (DOI)000174181800025 ()2-s2.0-79955995101 (Scopus ID)
Note

NR 20150402

Available from: 2015-03-12 Created: 2015-03-11 Last updated: 2024-03-04Bibliographically approved
Janson, M. S., Hallén, A., Linnarsson, M. K., Nordell, N., Karlsson, S. & Svensson, B. G. (2001). Dissociation energy of the passivating hydrogen-aluminum complex in 4H-SiC. In: Materials Science Forum: . Paper presented at 3rd European Conference on Silicon Carbide and Related Materials (pp. 427-430). , 353-356
Open this publication in new window or tab >>Dissociation energy of the passivating hydrogen-aluminum complex in 4H-SiC
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2001 (English)In: Materials Science Forum, 2001, Vol. 353-356, p. 427-430Conference paper, Published paper (Other academic)
Abstract [en]

The thermal stability of the passivating hydrogen-aluminum complex ((HAl)-H-2) in 4H-silicon carbide has been studied by determining the effective diffusion constant for hydrogen in an AI-doped epitaxial layer. Assuming a complex comprised of one H-2 and one AI acceptor ion, the extracted diffusivities provide the dissociation frequency of the complex. The extracted frequencies cover three orders of magnitude and yield a close to perfect fit to an Arrhenius equation with the extracted dissociation energy for the (HAl)-H-2-complex equal to 1.66 (+/-0.05) eV and a pre-exponential attempt frequency nu (0) = 1.7x10(13) s(-1) in good agreement with the expected value for a first order dissociation process.

Series
Materials Science Forum, ISSN 0255-5476
Keywords
hydrogen, passivation, SIMS
National Category
Engineering and Technology
Identifiers
urn:nbn:se:kth:diva-29570 (URN)10.4028/www.scientific.net/MSF.353-356.427 (DOI)000168535200104 ()2-s2.0-14344271944 (Scopus ID)
Conference
3rd European Conference on Silicon Carbide and Related Materials
Note

QC 20110208

Available from: 2011-02-08 Created: 2011-02-08 Last updated: 2022-06-25Bibliographically approved
Bowallius, O., Anand, S., Nordell, N., Landgren, G. & Karlsson, S. (2001). Scanning capacitance microscopy investigations of SiC structures. Materials Science in Semiconductor Processing, 4(03-jan), 209-211
Open this publication in new window or tab >>Scanning capacitance microscopy investigations of SiC structures
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2001 (English)In: Materials Science in Semiconductor Processing, ISSN 1369-8001, E-ISSN 1873-4081, Vol. 4, no 03-jan, p. 209-211Article in journal (Refereed) Published
Abstract [en]

We have applied scanning capacitance microscopy (SCM) to investigate SIC structures grown by vapour-phase epitaxy. The SCM technique is evaluated using n- and p-type doping staircase structures with doping concentrations ranging from 10(16) to 10(20) cm(-3). The n- and p-type doping was obtained by doping SiC with nitrogen and aluminium, respectively. The sample cross-sections for SCM were obtained by simple cleaving. For doping levels above 10(17) cm(-3) the SCM data are consistent with doping data obtained independently from secondary ion mass spectroscopy (SIMS). Treating the samples with diluted hydrofluoric acid significantly improves the SCM signal for the low-doped regions. The SCM technique has been used to investigate doping redistribution in patterned regrowth of n- and p-type SIC around dry-etched mesas. In both cases, contrast variations were seen close to the mesa walls, indicative of doping variations; lower and higher incorporation for p- and n-type, respectively. The observations are shown to be consistent with the expected trends in dopant incorporation in the SiC material.

Keywords
SCM, SiC, doping incorporation, regrowth
National Category
Engineering and Technology
Identifiers
urn:nbn:se:kth:diva-20483 (URN)10.1016/S1369-8001(00)00132-3 (DOI)000167727200048 ()2-s2.0-0035246821 (Scopus ID)
Note

QC 20100525

Available from: 2010-08-10 Created: 2010-08-10 Last updated: 2022-09-13Bibliographically approved
Kassamakova, L., Kakanakov, R., Kassamakov, I., Nordell, N., Savage, S., Svedberg, E. B. & Madsen, L. D. (2000). Al/Si ohmic contacts to p-type 4H-SiC for power devices. In: SILICON CARBIDE AND RELATED MATERIALS - 1999 PTS, 1 & 2: . Paper presented at International Conference on Silicon Carbide and Related Materials, OCT 10-15, 1999, RES TRIANGLE PK, NORTH CAROLINA (pp. 1009-1012).
Open this publication in new window or tab >>Al/Si ohmic contacts to p-type 4H-SiC for power devices
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2000 (English)In: SILICON CARBIDE AND RELATED MATERIALS - 1999 PTS, 1 & 2, 2000, p. 1009-1012Conference paper, Published paper (Refereed)
Series
MATERIALS SCIENCE FORUM, ISSN 0255-5476 ; 338-3
National Category
Engineering and Technology
Identifiers
urn:nbn:se:kth:diva-161280 (URN)10.4028/www.scientific.net/MSF.338-342.1009 (DOI)000165996700245 ()2-s2.0-18844470023 (Scopus ID)
Conference
International Conference on Silicon Carbide and Related Materials, OCT 10-15, 1999, RES TRIANGLE PK, NORTH CAROLINA
Note

NR 20150402

Available from: 2015-03-12 Created: 2015-03-11 Last updated: 2022-06-23Bibliographically approved
Janson, M. S., Hallén, A., Linnarsson, M. K., Svensson, B. G., Nordell, N. & Karlsson, S. (2000). Electric-field-assisted migration and accumulation of hydrogen in silicon carbide. Physical Review B. Condensed Matter and Materials Physics, 61(11), 7195-7198
Open this publication in new window or tab >>Electric-field-assisted migration and accumulation of hydrogen in silicon carbide
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2000 (English)In: Physical Review B. Condensed Matter and Materials Physics, ISSN 1098-0121, E-ISSN 1550-235X, Vol. 61, no 11, p. 7195-7198Article in journal (Refereed) Published
Abstract [en]

The diffusion of deuterium (H-2) in epitaxial 4H-SiC layers with buried highly Al-acceptor doped regions has been studied by secondary ion mass spectrometry. H-2 was introduced in the near surface region by the use of 20-keV implantation after which the samples were thermally annealed. As a result, an anomalous accumulation of H-2 in the high doped layers was observed. To explain the accumulation kinetics, a model is proposed where positively charged H-2 ions are driven into the high doped layer and become trapped there by the strong electric field at the edges. This effect is important for other semiconductors as well, since hydrogen is a common impurity present at high concentrations in many semiconductors.

Keywords
6h
National Category
Engineering and Technology
Identifiers
urn:nbn:se:kth:diva-19645 (URN)10.1103/PhysRevB.61.7195 (DOI)000086031200010 ()2-s2.0-0001726503 (Scopus ID)
Note

QC 20150625

Available from: 2010-08-10 Created: 2010-08-10 Last updated: 2022-06-25Bibliographically approved
Romano-Rodriguez, A., Perez-Rodriguez, A., Serre, C., Morante, J. R., Esteve, J., Acero, M. C., . . . Van Landuyt, J. (2000). Epitaxial growth of beta-SiC on ion-beam synthesized beta-SiC: Structural characterization. In: Silicon Carbide and Related Materials - 1999 Pts, 1 & 2: . Paper presented at ICSCRM '99: The International Conference on Silicon Carbide and Related Materials, Research Triangle Park, NC, USA, , 10 October 1999 through 15 October 1999 (pp. 309-312). Trans Tech Publications Inc.
Open this publication in new window or tab >>Epitaxial growth of beta-SiC on ion-beam synthesized beta-SiC: Structural characterization
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2000 (English)In: Silicon Carbide and Related Materials - 1999 Pts, 1 & 2, Trans Tech Publications Inc., 2000, p. 309-312Conference paper, Published paper (Refereed)
Abstract [en]

In this work we present for the first time, to our knowledge, the CVD epitaxial growth of β-SiC using an ion beam synthesized (IBS) β-SiC layer as seed, which has been formed by multiple implantation into Si wafers at 500 °C. The ion beam synthesized continuous layer is constituted by β-SiC nanocrystals that are well oriented relative to the silicon substrate. Comparison of the epitaxial growth on these samples with that on silicon test samples, both on and off-axis, is performed. The results show that the epitaxial growth can be achieved on the IBS samples without the need of the carbonization step and that the structural quality of the CVD layer is comparable to that obtained on a carbonized silicon sample. Improvement of the quality of the deposited layer is proposed.

Place, publisher, year, edition, pages
Trans Tech Publications Inc., 2000
Series
Materials Science Forum, ISSN 0255-5476 ; 338
Keywords
CVD growth, FTIR, ion beam synthesis, TEM, XRD
National Category
Materials Engineering
Identifiers
urn:nbn:se:kth:diva-161279 (URN)10.4028/www.scientific.net/MSF.338-342.309 (DOI)000165996700075 ()2-s2.0-3142712525 (Scopus ID)
Conference
ICSCRM '99: The International Conference on Silicon Carbide and Related Materials, Research Triangle Park, NC, USA, , 10 October 1999 through 15 October 1999
Note

QC 20150313

Available from: 2015-03-12 Created: 2015-03-11 Last updated: 2022-06-23Bibliographically approved
Organisations
Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0002-4148-5679

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