Dr Igor Marko
Research Staff
Qualifications: PhD
Email: i.marko@surrey.ac.uk
Phone: Work: 01483 68 6161
Room no: 16 ATI 02
Further information
Biography
Igor Pavlovich Marko was born in 1974 in Belarus. He graduated with distinction from the department of quantum radiophysics and optoelectronics of the Belarusian State University in 1996. From 1996 until 2001 he studied the optical properties of ZnSe- and GaN-based wide bandgap semiconductors and optically pumped lasers in the Laboratory of Semiconductor Optics of B. I. Stepanov Institute of Physics of the Belarusian Academy of Sciences. He received the degree of PhD in 2000 (thesis: "Optically Pumped Lasers Based on ZnSe Epitaxial Layers and ZnMgSSe/ZnSe Quantum Well Heterostructures"). Since 2001 have been studying the properties of near-IR and mid-IR III-V based interband quantum dots, quantum well lasers, short-wavelength (<3.5um) quantum cascade lasers, InGaNAs avalanche photodiodes at the University of Surrey. Most recent activity includes developing of a new III-V material systems containing Bi.
Research Interests
My current research interests includes III-V visible light-emitting diodes and lasers, near-infrared quantum dot and quantum well lasers for telecommunications, avalanche photo-diodes for 1.3-1.5μm spectral range, mid-infrared interband and quantum cascade lasers. Most recent projects include developing of a new III-V material systems containing Bi (GaAsBi/GaAs, InGaAsBi/InP).
Publications
Highlights
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(2010) 'Efficiency limiting processes in 1.55 mu m InAs/InP-based quantum dots lasers'. AMER INST PHYSICS APPLIED PHYSICS LETTERS, 97 (16) Article number ARTN 161104 doi: 10.1063/1.3504253Full text is available at: http://epubs.surrey.ac.uk/7903/
- . (2009) 'The Importance of Recombination via Excited States in InAs/GaAs 1.3 mu m Quantum-Dot Lasers'. IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC IEEE J SEL TOP QUANT, 15 (3), pp. 799-807.
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(2007) 'Temperature and pressure dependence of the recombination processes in 1.5 mu m InAs/InP (311)B quantum dot lasers'. AMER INST PHYSICS APPLIED PHYSICS LETTERS, 91 (13) Article number ARTN 131113 doi: 10.1063/1.2790777Full text is available at: http://epubs.surrey.ac.uk/531967/
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(2006) 'Temperature dependence of the gain in p-doped and intrinsic 1.3 mu m InAs/GaAs quantum dot lasers'. AMER INST PHYSICS APPLIED PHYSICS LETTERS, 89 (19) Article number ARTN 191118 doi: 10.1063/1.2387114Full text is available at: http://epubs.surrey.ac.uk/531963/
Journal articles
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(2012) 'Improved optoelectronic properties of rapid thermally annealed dilute nitride GaInNAs photodetectors'. IEEE Journal of Electronic Materials, 41 (12), pp. 3393-3401.Full text is available at: http://epubs.surrey.ac.uk/745030/
Abstract
We investigate the optical and electrical characteristics of GaInNAs/GaAs long-wavelength photodiodes grown under varying conditions by molecular beam epitaxy and subjected to postgrowth rapid thermal annealing (RTA) at a series of temperatures. It is found that the device performance of the nonoptimally grown GaInNAs p-i-n structures, with nominal compositions of 10% In and 3.8% N, can be improved significantly by the RTA treatment to match that of optimally grown structures. The optimally annealed devices exhibit overall improvement in optical and electrical characteristics, including increased photoluminescence brightness, reduced density of deep-level traps, reduced series resistance resulting from the GaAs/GaInNAs heterointerface, lower dark current, and significantly lower background doping density, all of which can be attributed to the reduced structural disorder in the GaInNAs alloy.© 2012 TMS.
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(2012) 'Temperature and Bi-concentration dependence of the bandgap and spin-orbit splitting in InGaBiAs/InP semiconductors for mid-infrared applications'. Applied Physics Letters, 101 (22)doi: 10.1063/1.4768532
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(2012) 'Cavity mode gain alignment in GaAsSb-based near-infrared vertical cavity lasers studied by spectroscopy and device measurements'. Journal of Applied Physics, 112 (3)doi: 10.1063/1.4744985Full text is available at: http://epubs.surrey.ac.uk/728516/
Abstract
We present a combination of spectroscopy and device measurements on GaAsSb/GaAs vertical-cavity surface-emitting laser (VCSEL) structures to determine the temperature at which the wavelength of the VCSEL cavity mode (CM) aligns with that of the quantum well (QW) ground-state transition (GST), and therefore the gain peak. We find that, despite the achievement of room temperature (RT) continuous wave lasing in VCSEL devices, the QW transition and the CM are actually slightly misaligned at this temperature; room temperature electroluminescence measurements from a cleaved edge of the VCSEL wafer indicate that the 300 K QW GST energy is at 0.975 ± 0.005 eV, while the CM measured in the VCSEL surface reflectivity spectra is at 0.9805 ± 0.0002 eV. When the wafer sample is cooled, the CM and QW GST can be brought into alignment at 270 ± 10 K, as confirmed by temperature-dependent electro-modulated reflectance (ER) and edge-electroluminescence spectroscopic studies. This alignment temperature is further confirmed by comparing the temperature dependence of the emission energy of a fabricated VCSEL device with that of an edge-emitting laser structure with a nominally identical active region. The study suggests that for further device improvement, the room temperature CM and QW GST energies should be more closely matched and both designed to a smaller energy of about 0.95 eV, somewhat closer to the 1.31 μm target. The study amply demonstrates the usefulness of non-destructive ER characterisation techniques in VCSEL manufacturing with GaAsSb-based QWs. © 2012 American Institute of Physics.
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(2012) 'Recombination mechanisms and band alignment of GaAs1-xBix/GaAs light emitting diodes'. APPLIED PHYSICS LETTERS, 100 (5) Article number ARTN 051105 doi: 10.1063/1.3681139Full text is available at: http://epubs.surrey.ac.uk/531960/
- . (2012) 'InGaBiAs/InP semiconductors for mid-infrared applications: Dependence of bandgap and spin-orbit splitting on temperature and bismuth content'. ICP 2012 - 3rd International Conference on Photonics 2012, Proceedings, , pp. 154-158.
- . (2012) 'Improved Optoelectronic Properties of Rapid Thermally Annealed Dilute Nitride GaInNAs Photodetectors'. Journal of Electronic Materials, , pp. 1-9.
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(2011) 'Modulation of the absorption coefficient at 1.3 mu m in Ge/SiGe multiple quantum well heterostructures on silicon'. OPTICS LETTERS, 36 (21), pp. 4158-4160.doi: 10.1364/OL.36.004158Full text is available at: http://epubs.surrey.ac.uk/531961/
Abstract
We report modulation of the absorption coefficient at 1.3 μm in Ge/SiGe multiple quantum well heterostructures on silicon via the quantum-confined Stark effect. Strain engineering was exploited to increase the direct optical bandgap in the Ge quantum wells. We grew 9 nm-thick Ge quantum wells on a relaxed Si0.22Ge0.78 buffer and a contrast in the absorption coefficient of a factor of greater than 3.2 was achieved in the spectral range 1290–1315 nm.
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(2011) 'Direct evidence for suppression of Auger recombination in GaInAsSbP/InAs mid-infrared light-emitting diodes'. AMER INST PHYSICS APPL PHYS LETT, 99 (14) Article number 141110 doi: 10.1063/1.3646910Full text is available at: http://epubs.surrey.ac.uk/7898/
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(2011) 'Influence of de-tuning and non-radiative recombination on the temperature dependence of 1.3 mu m GaAsSb/GaAs vertical cavity surface emitting lasers'. AMER INST PHYSICS APPLIED PHYSICS LETTERS, 99 (7) Article number ARTN 071110 doi: 10.1063/1.3625938Full text is available at: http://epubs.surrey.ac.uk/7832/
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(2011) 'Temperature dependence of 4.1 mu m mid-infrared type II "W" interband cascade lasers'. AMER INST PHYSICS APPLIED PHYSICS LETTERS, 99 (2) Article number ARTN 021102 doi: 10.1063/1.3606533Full text is available at: http://epubs.surrey.ac.uk/7891/
- . (2011) 'GaInNAsSb/GaAs Photodiodes for Long-Wavelength Applications'. IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC IEEE ELECTRON DEVICE LETTERS, 32 (7), pp. 919-921.
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(2010) 'Efficiency limiting processes in 1.55 mu m InAs/InP-based quantum dots lasers'. AMER INST PHYSICS APPLIED PHYSICS LETTERS, 97 (16) Article number ARTN 161104 doi: 10.1063/1.3504253Full text is available at: http://epubs.surrey.ac.uk/7903/
- . (2010) 'Thermal Characteristics of 1.55-mu m InGaAlAs Quantum Well Buried Heterostructure Lasers'. IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC IEEE JOURNAL OF QUANTUM ELECTRONICS, 46 (5), pp. 700-705.
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(2010) 'Physical properties of short wavelength 2.6μm InAs/AlSb-based quantum cascade lasers'. IEEE Conference Digest - IEEE International Semiconductor Laser Conference, , pp. 95-96.Full text is available at: http://epubs.surrey.ac.uk/104831/
Abstract
We used high hydrostatic pressure techniques to understand the deteriorating temperature performance with decreasing wavelength of short wavelength quantum cascade lasers. Influence of inter-valley scattering and distribution of the electron wave functions will be discussed.
- . (2009) 'The Importance of Recombination via Excited States in InAs/GaAs 1.3 mu m Quantum-Dot Lasers'. IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC IEEE J SEL TOP QUANT, 15 (3), pp. 799-807.
- . (2009) 'Temperature insensitive quantum dot lasers: are we really there yet?'. SPRINGER JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS, London, ENGLAND: 20, pp. 272-276.
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(2007) 'Temperature and pressure dependence of the recombination processes in 1.5 mu m InAs/InP (311)B quantum dot lasers'. AMER INST PHYSICS APPLIED PHYSICS LETTERS, 91 (13) Article number ARTN 131113 doi: 10.1063/1.2790777Full text is available at: http://epubs.surrey.ac.uk/531967/
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(2006) 'Temperature dependence of the gain in p-doped and intrinsic 1.3 mu m InAs/GaAs quantum dot lasers'. AMER INST PHYSICS APPLIED PHYSICS LETTERS, 89 (19) Article number ARTN 191118 doi: 10.1063/1.2387114Full text is available at: http://epubs.surrey.ac.uk/531963/
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(2006) 'Carrier recombination in 1.3 mu m GaAsSb/GaAs quantum well lasers'. AMER INST PHYSICS APPLIED PHYSICS LETTERS, 89 (17) Article number ARTN 173509 doi: 10.1063/1.2369649Full text is available at: http://epubs.surrey.ac.uk/104830/
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(2005) 'Carrier transport and recombination in p-doped and intrinsic 1.3 mu m InAs/GaAs quantum-dot lasers'. AMER INST PHYSICS APPLIED PHYSICS LETTERS, 87 (21) Article number ARTN 211114 doi: 10.1063/1.2135204
- . (2005) 'Effect of gain saturation and nonradiative recombination on the thermal characteristics of InAs/GaAs 1.3 mu m quantum dot lasers'. IEEE 2005 IEEE LEOS Annual Meeting Conference Proceedings (LEOS), Sydney, AUSTRALIA: , pp. 401-402.
- . (2005) 'The influence of p-doping on the temperature sensitivity of 1.3 mu m quantum dot lasers'. IEEE 2005 IEEE LEOS Annual Meeting Conference Proceedings (LEOS), Sydney, AUSTRALIA: , pp. 603-604.
- . (2003) 'The role of Auger recombination in InAs 1.3-/mu m quantum-dot lasers investigated using high hydrostatic pressure'. IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC IEEE JOURNAL OF SELECTED TOPICS IN QUANTUM ELECTRONICS, 9 (5), pp. 1300-1307.
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(2003) 'Importance of Auger recombination in InAs 1.3 mu m quantum dot lasers'. IEE-INST ELEC ENG ELECTRONICS LETTERS, 39 (1), pp. 58-59.doi: 10.1049/el:20030014
Conference papers
- . (2011) 'Strain engineering of the electroabsorption response in Ge/SiGe multiple quantum well heterostructures'. IEEE 8th IEEE International Conference on Group IV Photonics, London, UK: Group IV Photonics, pp. 107-108.
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(2010) 'Waveguides for mid-infrared group IV photonics'. Proceedings of IEEE 7th International Conference on Group IV Photonics, Beijing, China: 7th IEEE GFP, pp. 374-376.Full text is available at: http://epubs.surrey.ac.uk/733170/
Abstract
In this paper we present preliminary work on group IV photonic waveguides that may be suitable for mid-infrared wavelengths. Fabrication and experimental results for two waveguide structures are given.
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(2010) 'Temperature sensitivity of 1.55μm (100) InAs/InP-based quantum dot lasers'. IEEE Proceedings of 22nd International Conference on Indium Phosphide and Related Materials, Kagawa, Japan: 22nd IPRM, pp. 23-24.Full text is available at: http://epubs.surrey.ac.uk/733175/
Abstract
Semiconductor lasers with quantum dot (QD) based active regions have generated a huge amount of interest for applications including communications networks due to their anticipated superior physical properties due to three dimensional carrier confinement. For example, the threshold current of ideal quantum dots is predicted to be temperature insensitive. We have investigated the operating characteristics of 1.55 μm InAs/InP (100) quantum dot lasers focusing on their carrier recombination characteristics using a combination of low temperature and high pressure measurements. By measuring the intrinsic spontaneous emission from a window fabricated in the n-contact of the devices we have measured the radiative component of the threshold current density, Jrad. We find that Jrad is itself relatively temperature insensitive (Fig. 1). However, the total threshold current density, Jth, increases significantly with temperature leading to a characteristic temperature T0~72 K around 220 K-290 K. From this data it is clear that the devices are dominated by a non-radiative recombination process which accounts for up to 94% of the threshold current at room temperature (Fig. 1).
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(2010) 'Thermal performance of 1.55μm InGaAlAs quantum well buried heterostructure lasers'. IEEE Proceedings of 22nd International Conference on Indium Phosphide and Related Materials, Kagawa, Japan: 22nd IPRM, pp. 265-268.Full text is available at: http://epubs.surrey.ac.uk/733176/
Abstract
We have investigated the threshold current Ith and differential quantum efficiency as the function of temperature in InGaAlAs/InP multiple quantum well (MQWs) buried heterostructure (BH) lasers. We find that the temperature sensitivity of Ith is due to non-radiative recombination which accounts for up to ~80% of Jth at room temperature. Analysis of spontaneous emission emitted from the devices show that the dominant non-radiative recombination process is consistent with Auger recombination. We further show that the above threshold differential internal quantum efficiency, ηi, is ~80% at 20°C remaining stable up to 80°C. In contrast, the internal optical loss, αi, increases from 15 cm-1 at 20°C to 22 cm-1 at 80°C, consistent with inter-valence band absorption (IVBA). This suggests that the decrease in power output at elevated temperatures is associated with both Auger recombination and IVBA.
- . (2010) 'Efficiency limitations of green InGaN LEDs and laser diodes'. 22nd IEEE International Semiconductor Laser Conference, Kyoto, Japan: ISLC 2010, pp. 27-28.
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(2010) 'Reduction of dark current and unintentional background doping in InGaAsN photodetectors by ex situ annealing'. SPIE Proceedings of SPIE - Posters Session, Brussels, Belgium: Optical Sensing and Detection 7726doi: 10.1117/12.853912Full text is available at: http://epubs.surrey.ac.uk/733177/
Abstract
InGaAsN is a promising material system to enable low-cost GaAs-based detectors to operate in the telecommunication spectrum, despite the problems posed by the low growth temperature required for nitrogen incorporation. We demonstrate that InGaAsN p+-i-n+ structures with nominal In and N fraction of 10% and 3.8%, grown by molecular beam epitaxy (MBE) under non-optimal growth conditions, can be optimized by post growth thermal annealing to match the performance of optimally grown structures. We report the findings of an annealing study by comparing the photoluminescence spectra, dark current and background concentration of the as-grown and annealed samples. The dark current of the optimally annealed sample is approximately 2 μA/cm2 at an electric field of 100 kV/cm, and is the lowest reported to date for InGaAsN photodetectors with a cut-off wavelength of 1.3 μm. Evidence of lower unintentional background concentration after annealing at a sufficiently high temperature, is also presented.
- . (2010) 'Thermal behavior of 1.55 μm (100) InAs/InP-based quantum dot lasers'. IEEE Poceeedings of 22nd International Semiconductor Laser Conference, Kyoto, Japan: ISLC 2010, pp. 75-76.
- . (2010) 'Temperature sensitivity of mid-infrared type II "W" interband cascade lasers (ICL) emitting at 4.1μm at room temperature'. IEEE 22nd IEEE International Semi-conductor Laser Conference, Kyoto, Japan: ISLC 2010, pp. 41-42.
- . (2009) 'Gain peak-cavity mode alignment optimisation in buried tunnel junction mid-infrared GaSb vertical cavity surface emitting lasers using hydrostatic pressure'. INST ENGINEERING TECHNOLOGY-IET IET OPTOELECTRONICS, Cardiff, WALES: Semiconductor and Integrated Optoelectronics Conference (SIOE 2009) 3 (6), pp. 305-309.
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(2009) 'Band-structure and gain-cavity tuning of 2.4-μm GaSb buried tunnel junction VCSELs'. Proceedings of European Conference on Lasers and Electro-Optics 2009 and the European Quantum Electronics Conference, Munich, Germany: CLEO Europe - EQEC 2009Full text is available at: http://epubs.surrey.ac.uk/104829/
Abstract
Low-cost, continuous-wave GaSb-based vertical cavity surface emitting lasers (VCSELs) operating at ~ 2.4 mum up to 50degC have been demonstrated recently. In this work we have used high pressure techniques to investigate ways to improve their performance and extend their working temperature range. Since the band-gap and energy of the gain peak (Ep) increase with pressure at 0.126 meV/MPa at constant temperature, when applied to edge emitting lasers (EEL) we can use pressure to determine the radiative and non-radiative recombination processes occurring. In the VCSEL the pressure dependence of the threshold current, is much more complicated. At the higher temperature the decreasing Auger recombination initially dominates. Therefore we predict that either increasing the band gap or increasing the operating wavelength will allow an improved temperature performance of these GaSb-based VCSELs.
- . (2009) 'Evidence of carrier leakage into the L-valley in InAs-based quantum cascade lasers under high hydrostatic pressure'. WILEY-V C H VERLAG GMBH PHYSICA STATUS SOLIDI B-BASIC SOLID STATE PHYSICS, Fortaleza, BRAZIL: 13th International Conference on High Pressure Semiconductor Physics (HPSP-13) 246 (3), pp. 512-515.
- . (2009) 'Dark current mechanisms in InxGa1-xAs 1-yNy'. IEEE IEEE Proceedings of LEOS Annual Meeting Conference, Belek-Antalya, Turkey: LEOS '09, pp. 233-234.
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(2009) 'The effect of hydrostatic pressure on the operation of quantum cascade lasers'. SPIE-INT SOC OPTICAL ENGINEERING QUANTUM SENSING AND NANOPHOTONIC DEVICES VI, San Jose, CA: Conference on Quantum Sensing and Nanophotonic Devices VI 7222doi: 10.1117/12.814322Full text is available at: http://epubs.surrey.ac.uk/733182/
- . (2008) 'Reliable 1550nm SI BH lasers fabricated using an improved Ru precursor'. 20th International Conference on Indium Phosphide and Related Materials, Versailles, France: IPRM 2008
- . (2008) 'Gamma-L scattering in InAs-based quantum cascade lasers studied using high hydrostatic pressure'. IEEE 2008 IEEE 21ST INTERNATIONAL SEMICONDUCTOR LASER CONFERENCE, Sorrento, ITALY: IEEE 21st International Semiconductor Laser Conference, pp. 47-48.
- . (2008) 'Thermal characteristics of 1.3 mu m GaAsSb/GaAs-based Edge- and Surface-emitting Lasers'. IEEE 2008 IEEE 21ST INTERNATIONAL SEMICONDUCTOR LASER CONFERENCE, Sorrento, ITALY: IEEE 21st International Semiconductor Laser Conference, pp. 83-84.
- . (2008) 'The importance of recombination via excited states in InAs/GaAs 1.3μm quantum dot lasers'. IEEE IEEE Proceedings of 21st International Semiconductor Laser Conference, Sorento, Italy: 21st ISLC 2008, pp. 117-118.
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(2007) 'Recombination, transport and loss mechanisms in p-doped InAs/GaAs quantum dots'. AMER INST PHYSICS Physics of Semiconductors, Pts A and B, Vienna, AUSTRIA: 28th International Conference on the Physics of Semiconductors (ICPS-28) 893, pp. 837-838.Full text is available at: http://epubs.surrey.ac.uk/733188/
- . (2007) 'Band gap dependence of the recombination processes in InAs/GaAs quantum dots studied using hydrostatic pressure'. WILEY-V C H VERLAG GMBH PHYSICA STATUS SOLIDI B-BASIC SOLID STATE PHYSICS, Barcelona, SPAIN: 12th International Conference on High Pressure Semiconductor Physics (HPSP-12) 244 (1), pp. 82-86.
- . (2007) 'Temperature and pressure dependence of carrier recombination processes in GaAsSb/GaAs quantum well lasers'. WILEY-V C H VERLAG GMBH PHYSICA STATUS SOLIDI B-BASIC SOLID STATE PHYSICS, Barcelona, SPAIN: 12th International Conference on High Pressure Semiconductor Physics (HPSP-12) 244 (1), pp. 197-202.
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(2007) 'The influence of carrier density non-pinning on the output power of 1.55 μm lasers at high temperature'. IEEE Lasers and Electro-Optics, 2007 and the International Quantum Electronics Conference, Munich, Germany: CLEOE-IQEC 2007, pp. 1-1.Full text is available at: http://epubs.surrey.ac.uk/531969/
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(2006) 'Intrinsic limitations of p-doped and undoped 1.3 μm InAs/GaAs quantum dot lasers'. IEEE 20th IEEE International Semi-conductor Laser Conference - Conference Digest, Hawaii, USA: ISLC 2006, pp. 143-144.Full text is available at: http://epubs.surrey.ac.uk/531968/
Abstract
The temperature dependencies of the recombination and gain processes reveal intrinsic limitations on the performances of quantum dot lasers. Controlling the transport of the carriers using the inhomogeneous broadening makes temperature stable threshold current possible
- . (2005) 'Recombination and loss mechanisms in low-threshold InAs-GaAs 1.3-mu m quantum-dot lasers'. IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC IEEE JOURNAL OF SELECTED TOPICS IN QUANTUM ELECTRONICS, Matsue, JAPAN: 19th IEEE International Semiconductor Laser Conference 11 (5), pp. 1041-1047.
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(2005) 'The influence of auger processes on recombination in long-wavelength InAs/GaAs quantum dots'. AMER INST PHYSICS Physics of Semiconductors, Pts A and B, Flagstaff, AZ: 27th International Conference on the Physics of Semiconductors (ICPS-27) 772, pp. 681-682.Full text is available at: http://epubs.surrey.ac.uk/733564/
- . (2004) 'Recombination mechanisms in InAs/InP quantum dash lasers studied using high hydrostatic pressure'. WILEY-V C H VERLAG GMBH PHYSICA STATUS SOLIDI B-BASIC RESEARCH, Berkeley, CA: 11th International Conference on High-Pressure Semiconductor Physics (HPSP-11) 241 (14), pp. 3427-3431.
- . (2004) 'Recombination and loss mechanisms in low-threshold InAs/GaAs 1.3 mu m quantum dot lasers'. IEEE 2004 IEEE 19TH INTERNATIONAL SEMICONDUCTOR LASER CONFERENCE, CONFERENCE DIGEST, Matsue, JAPAN: 19th IEEE International Semiconductor Laser Conference, pp. 57-58.
- . (2004) 'Experimental investigations into the thermal properties of 1.5-1.8-mu m InAs/InP quantum dash lasers'. IEEE 2004 IEEE 19TH INTERNATIONAL SEMICONDUCTOR LASER CONFERENCE, CONFERENCE DIGEST, Matsue, JAPAN: 19th IEEE International Semiconductor Laser Conference, pp. 61-62.
- . (2003) 'Long wavelength lasers on GaAs substrates'. IEE-INST ELEC ENG IEE PROCEEDINGS-CIRCUITS DEVICES AND SYSTEMS, MUMBAI, INDIA: 6th International Conference on Optoelectronics, Fibre Optics and Photonics 150 (6), pp. 521-528.
- . (2003) 'High-pressure studies of the recombination processes, threshold currents, and lasing wavelengths in InAs/GaInAs quantum dot lasers'. WILEY-V C H VERLAG GMBH PHYSICA STATUS SOLIDI B-BASIC RESEARCH, UNIV SURREY, GUILDFORD, ENGLAND: 10th International Conference on High Pressures in Semiconductor Physics (HPSP-X) 235 (2), pp. 407-411.