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Materials and Processing Technologies for Advanced Electronic and Photonic Devices
KTH, School of Information and Communication Technology (ICT), Integrated Devices and Circuits.ORCID iD: 0000-0002-0123-551X
2014 (English)Doctoral thesis, comprehensive summary (Other academic)
Place, publisher, year, edition, pages
stockholm: KTH Royal Institute of Technology, 2014. , 84 p.
Series
TRITA-ICT/MAP AVH, ISSN 1653-7610 ; 2014:15
National Category
Engineering and Technology
Identifiers
URN: urn:nbn:se:kth:diva-157138ISBN: 978-91-7595-351-9 (print)OAI: oai:DiVA.org:kth-157138DiVA: diva2:769324
Public defence
2014-12-17, Sal/Hal A, Electrum, KTH-ICT, Kista, 10:00 (English)
Opponent
Supervisors
Note

QC 20141208

Available from: 2014-12-08 Created: 2014-12-07 Last updated: 2014-12-08Bibliographically approved
List of papers
1. Optical loss and interface morphology in AlGaAs/GaAs distributed Bragg reflectors
Open this publication in new window or tab >>Optical loss and interface morphology in AlGaAs/GaAs distributed Bragg reflectors
2007 (English)In: Applied Physics Letters, ISSN 0003-6951, E-ISSN 1077-3118, Vol. 91, no 10, 101101- p.Article in journal (Refereed) Published
Abstract [en]

It is shown that n-type doping of AlGaAs/GaAs distributed Bragg reflectors (DBRs) grown by metal-organic vapor-phase epitaxy has a profound negative impact on the performance of vertical-cavity surface-emitting lasers (VCSELs) based on such mirrors. Using an intracavity contact scheme, 1.3-mu m-range InGaAs VCSELs with and without doping in the bottom DBR are directly compared. Doped mirrors lead to lower slope efficiency, lower output power, and higher threshold current. From x-ray diffraction, high-accuracy reflectance measurements, and atomic force microscopy studies, it is suggested that this performance degradation is due to the doping-enhanced Al-Ga interdiffusion, leading to interface roughening and increased scattering loss.

Keyword
Metallorganic vapor phase epitaxy; Optical losses; Semiconducting aluminum compounds; Semiconductor doping; Surface emitting lasers; X ray diffraction; High-accuracy reflectance measurements; Interface morphology; Vertical-cavity surface-emitting lasers (VCSELs)
National Category
Condensed Matter Physics
Identifiers
urn:nbn:se:kth:diva-8625 (URN)10.1063/1.2779242 (DOI)000249322900001 ()2-s2.0-34548480155 (Scopus ID)
Note
QC 20100825Available from: 2008-06-03 Created: 2008-06-03 Last updated: 2017-12-14Bibliographically approved
2. On the long-wavelength optimization of highly strained InGaAs/GaAs quantum wells grown by metal-organic vapor-phase epitaxy
Open this publication in new window or tab >>On the long-wavelength optimization of highly strained InGaAs/GaAs quantum wells grown by metal-organic vapor-phase epitaxy
2008 (English)In: Journal of Crystal Growth, ISSN 0022-0248, E-ISSN 1873-5002, Vol. 310, no 13, 3163-3167 p.Article in journal (Refereed) Published
Abstract [en]

We have investigated the influence of the metal-organic vapor-phase epitaxy growth conditions on the long-wavelength optimization of InGaAs/GaAs quantum wells (QWs). It is found that the V/III ratio is a critical parameter for the in incorporation and wavelength extension, with a strong sensitivity even at very high values. Furthermore, it is noted that the exact crystallographic substrate surface orientation close to (001) may have a strong influence on the photoluminescence (PL) properties with a maximum PL wavelength for orientations within 0.01-0.03 degrees from (0 0 1). This is discussed in terms of changing interface morphology and growth modes with increasing misorientation. Finally, the application of antimony as surfactant is not found to have an improving effect on the layer integrity, whereas a slight extension of the emission wavelength indicates a small incorporation of antimony in the QWs.

Keyword
A1. Photoluminescence, A1. Substrates, A3. Metal-organic vapor-phase epitaxy, A3. Quantum wells, B2. InGaAs
National Category
Physical Sciences
Identifiers
urn:nbn:se:kth:diva-8029 (URN)10.1016/j.jcrysgro.2008.04.007 (DOI)000257353500007 ()2-s2.0-46549083875 (Scopus ID)
Note
QC 20100924. Uppdaterad från Manuskript till Artikel (20100924). Tidigare Titel "On the long wavelength optimization of highly strained InGaAs/GaAs grown by metal-organic vapor-phase epitaxy. Available from: 2008-02-25 Created: 2008-02-25 Last updated: 2017-12-14Bibliographically approved
3. High-temperature dynamics, high-speed modulation, and transmission experiments using 1.3-mu m InGaAs single-mode VCSELs
Open this publication in new window or tab >>High-temperature dynamics, high-speed modulation, and transmission experiments using 1.3-mu m InGaAs single-mode VCSELs
Show others...
2007 (English)In: Journal of Lightwave Technology, ISSN 0733-8724, E-ISSN 1558-2213, Vol. 25, no 9, 2791-2798 p.Article in journal (Refereed) Published
Abstract [en]

High-temperature dynamics, including small and large signal modulation response, of 1.28-ftm GaAs-based vertical-cavity surface-emitting lasers (VCSELs) with highly strained InGaAs quantum wells have been investigated. The VCSELs are oxide-confined with a relatively large oxide aperture for high output power and have a surface relief for fundamental mode operation. An inverted surface relief is used to improve manufacturability and to suppress oxide modes that otherwise appear in VCSELs with a large detuning, between the cavity resonance and the gain peak. The size dependence of the modulation bandwidth and bandwidth limitations are. investigated. A VCSEL with an optimum combination of oxide aperture and surface relief diameters produces clear open eyes with an extinction ratio of > 6 dB at OC-48 and 10-GbE bit rates from 25 degrees C to 85 degrees C under constant drive conditions. The same VCSEL is also shown to be capable of eiror-free transmission (BER < 10(-9)) over 9 km of standard single-mode fiber under the same conditions.

Keyword
high-speed modulation, InGaAs, inverted surface relief, single mode, vertical-cavity surface-emitting laser (VCSEL), surface-emitting lasers, oxide confined vcsels, 1.3 mu-m, suppression, relief
National Category
Other Physics Topics
Identifiers
urn:nbn:se:kth:diva-16947 (URN)10.1109/jlt.2007.903308 (DOI)000249350000060 ()2-s2.0-34548625210 (Scopus ID)
Note

QC 20100525

Available from: 2010-08-05 Created: 2010-08-05 Last updated: 2017-12-12Bibliographically approved
4. Fabrication of an electro-absorption transceiver with a monolithically integrated optical amplifier for fiber transmission of 40-60 GHz radio signals
Open this publication in new window or tab >>Fabrication of an electro-absorption transceiver with a monolithically integrated optical amplifier for fiber transmission of 40-60 GHz radio signals
Show others...
2011 (English)In: Semiconductor Science and Technology, ISSN 0268-1242, E-ISSN 1361-6641, Vol. 26, no 1, 014042- p.Article in journal (Refereed) Published
Abstract [en]

We report on the fabrication of a monolithically integrated semiconductor optical amplifier (SOA) and a reflective electro-absorption transceiver (EAT) for 40-60 GHz radio-over-fiber applications. The EAT can either function as a transmitter (reflective modulator) or as a receiver (photodetector) depending on operation mode. The SOA and the EAT sections are based on different InGaAsP multiple quantum-well active layers connected by a butt joint. Benzocyclobutene is used to reduce the capacitance beside the ridge mesa. Devices are designed to have a peaked response at the operating frequency through the design of microwave waveguides on top of the devices. The packaged device exhibits at 0.1 mW optical input power an amplified DC responsivity of 18.5 mA mW(-1) and a modulation efficiency of 0.67 mW V-1. The estimated radio frequency loss at 40 GHz of an optical link consisting of two SOA-EAT devices was 23 dB using an unmodulated optical input carrier to the transmitter of 0.94 mW.

National Category
Other Electrical Engineering, Electronic Engineering, Information Engineering Materials Engineering Condensed Matter Physics
Identifiers
urn:nbn:se:kth:diva-29355 (URN)10.1088/0268-1242/26/1/014042 (DOI)000285382000044 ()2-s2.0-79851471496 (Scopus ID)
Funder
EU, European Research Council, IST-035317
Note

QC 20110207

Available from: 2011-02-07 Created: 2011-02-01 Last updated: 2017-12-11Bibliographically approved
5. Analysis of surface oxides on narrow bandgap III-V semiconductors leading towards surface leakage free IR photodetectors
Open this publication in new window or tab >>Analysis of surface oxides on narrow bandgap III-V semiconductors leading towards surface leakage free IR photodetectors
Show others...
2012 (English)In: Proceedings of SPIE, the International Society for Optical Engineering, ISSN 0277-786X, E-ISSN 1996-756X, Vol. 8353, 835311- p.Article in journal (Refereed) Published
Abstract [en]

Narrow bandgap semiconductors GaSb, InAs, and InSb are important building blocks for infrared photodetectors based on type-II InSb quantum dots or an InAs/GaSb strained layer superlattice. Understanding the surface chemical composition of these materials can provide valuable information that enables optimization of device surface passivation techniques leading towards surface leakage free IR photodetectors. We report on an investigation into Ga-, In-, Sb-, and As-oxides and other chemical species on the surface of untreated, dry etched and thermally treated GaSb, InAs and InSb samples by x-ray photoelectron spectroscopy. The experimental results reveal the presence of Sb- and Ga-oxides on the surfaces of the untreated and treated GaSb samples. Both Sb- and In-oxides were observed on the surface of all InSb samples, and especially the dry etched sample had thicker oxide layers. In the case of the InAs samples, not only In-and As-oxides XPS signals were obtained, but also AsCl species were found on the ICP dry etched sample. These results helped to analyze the dark current of our fabricated IR detectors.

Keyword
Narrow bandgap III-V semiconductors, surface states, passivation, XPS, MWIR and LWIR photodetectors
National Category
Other Physics Topics
Identifiers
urn:nbn:se:kth:diva-157144 (URN)10.1117/12.919334 (DOI)000306604400036 ()2-s2.0-84901373778 (Scopus ID)
Conference
Conference on Infrared Technology and Applications XXXVIII, APR 23-27, 2012, Baltimore, MD
Note

QC 20141208

Available from: 2014-12-08 Created: 2014-12-08 Last updated: 2017-12-05Bibliographically approved
6. Long-wavelength infrared quantum-dot based interband photodetectors
Open this publication in new window or tab >>Long-wavelength infrared quantum-dot based interband photodetectors
Show others...
2011 (English)In: Infrared physics & technology, ISSN 1350-4495, E-ISSN 1879-0275, Vol. 54, no 3, 287-291 p.Article in journal (Refereed) Published
Abstract [en]

We report on the design and fabrication of (Al)GaAs(Sb)/InAs tensile strained quantum-dot (QD) based detector material for thermal infrared imaging applications in the long-wavelength infrared (LWIR) regime. The detection is based on transitions between confined dot states and continuum states in a type-II band lineup, and we therefore refer to it as a dot-to-bulk (D2B) infrared photodetector with expected benefits including long carrier lifetime due to the type-II band alignment, suppressed Shockley-Read-Hall generation-recombination due to the relatively large-bandgap matrix material, inhibited Auger recombination processes due to the tensile strain and epitaxial simplicity. Metal-organic vapor-phase epitaxy was used to grow multiple (Al)GaAs(Sb) QD layers on InAs substrates at different QD nominal thicknesses, compositions, doping conditions and multilayer periods, and the material was characterized using atomic force and transmission electron microscopy, and Fourier-transform infrared absorption spectroscopy. Dot densities up to 1 x 10(11) cm(-2), 1 x 10(12) cm(-2) and 3 x 10(10) cm(-2) were measured for GaAs, AlGaAs and GaAsSb QDs, respectively. Strong absorption in GaAs, AlGaAs and GaAsSb multilayer QD samples was observed in the wavelength range 6-12 mu m. From the wavelength shift in the spectral absorption for samples with varying QD thickness and composition it is believed that the absorption is due to an intra- valance band transition. From this it is possible to estimate the type-II inter-band transition wavelength, thereby suggesting that (Al)GaAs(Sb) QD/InAs heterostructures are suitable candidates for LWIR detection and imaging.

Keyword
Photodetector, LWIR, QD, MOVPE
National Category
Electrical Engineering, Electronic Engineering, Information Engineering
Identifiers
urn:nbn:se:kth:diva-34662 (URN)10.1016/j.infrared.2010.12.031 (DOI)000290973200028 ()2-s2.0-79955029475 (Scopus ID)
Note

QC 20110621 Ingår i konferens: International Conference on the Quantum Structure Infrared Photodector (QSIP), Istanbul, TURKEY, AUG 15-20, 2010

Available from: 2011-06-21 Created: 2011-06-13 Last updated: 2017-12-11Bibliographically approved
7. Planarization of epitaxial SiC trench structures by plasma ion etching
Open this publication in new window or tab >>Planarization of epitaxial SiC trench structures by plasma ion etching
Show others...
(English)Manuscript (preprint) (Other academic)
Identifiers
urn:nbn:se:kth:diva-157150 (URN)
Note

QS 2014

Available from: 2014-12-08 Created: 2014-12-08 Last updated: 2014-12-08Bibliographically approved
8. Full Epitaxial Trench Type Buried Grid SiC JBS Diodes
Open this publication in new window or tab >>Full Epitaxial Trench Type Buried Grid SiC JBS Diodes
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2014 (English)In: ECS Transactions, ISSN 1938-5862, E-ISSN 1938-6737, Vol. 64, no 7, 289-293 p.Article in journal (Refereed) Published
Abstract [en]

The paper presents the advanced concept of fully epitaxial SiC junction barrier Schottky (JBS) diodes. It combines trench etching with embedded epitaxial re-growth and enables cost-efficient manufacturing. Fabricated devices are rated for 20A / 1200V and have leakage currents below 0.1µA at 1000V blocking voltage.

National Category
Other Electrical Engineering, Electronic Engineering, Information Engineering
Identifiers
urn:nbn:se:kth:diva-157148 (URN)10.1149/06407.0289ecst (DOI)
Note

QC 20141208

Available from: 2014-12-08 Created: 2014-12-08 Last updated: 2017-12-05Bibliographically approved

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