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1.  New frontiers in InP based quantum devices
Manijeh Razeghi
Indium Phosphide and Related Materials, 2008. IPRM 2008. 20th International Conference on, pp.1,4, (2008)-- May 29, 2008 ...[Visit Journal]
Recent research activities taking place at center for quantum devices (CQD) based on InP material system, especially the exploration and demonstration of the state-of-art high performance quantum cascade lasers (QCL), greatly facilitate the understanding of the underlining physical principles governing the device operation. Thanks to the endless effort putting into the semiconductor epitaxy technologies, including the Molecular Beam Epitaxy (MBE) and low pressure metal organic chemical vapor deposition (LP-MOCVD), the world has seen a close approaching to the ultimate band gap engineering. Highly sophisticated man-made heterostructure, which incorporates hundreds of alternating layers of GaInAs/AlInAs with each layer thickness and composition specifically designed, can be created within a single growth. The material quality is evidenced by the atomically abrupt interfaces. The versatility of the band gap engineering is greatly enhanced by the strain-balanced technique, which allows for growing structures with continuously tunable conduction band offset with little defects. As a result, the room temperature continuous wave (CW) wall plug efficiency (WPE) and the maximum achievable output optical power from a single device have been constantly improving. Novel waveguide incorporating the photonic crystal distributed feedback (PCDFB) mechanism is also investigated with satisfactory preliminary results. [reprint (PDF)]
 
1.  Low frequency noise in 1024 x 1024 long wavelength infrared focal plane array base on Type-II InAs/GaSb superlattice
A. Haddadi, S.R. Darvish, G. Chen, A.M. Hoang, B.M. Nguyen and M. Razeghi
SPIE Proceedings, Vol. 8268, p. 82680X-- January 22, 2012 ...[Visit Journal]
Recently, the type-II InAs/GaSb superlattice (T2SL) material platform is considered as a potential alternative for HgCdTe technology in long wavelength infrared (LWIR) imaging. This is due to the incredible growth in the understanding of its material properties and improvement of device processing which leads to design and fabrication of better devices. In this paper, we report electrical low frequency noise measurement on a high performance type-II InAs/GaSb superlattice 1024×1024 LWIR focal plane array. [reprint (PDF)]
 
1.  Type-II Antimonide-based Superlattices for the Third Generation Infrared Focal Plane Arrays
Manijeh Razeghi, Edward Kwei-wei Huang, Binh-Minh Nguyen, Siamak Abdollahi Pour, and Pierre-Yves Delaunay
SPIE Proceedings, Infrared Technology and Applications XXXVI, Vol. 7660, pp. 76601F-- May 10, 2010 ...[Visit Journal]
In recent years, the Type-II superlattice (T2SL) material platform has seen incredible growth in the understanding of its material properties which has lead to unprecedented development in the arena of device design. Its versatility in band-structure engineering is perhaps one of the greatest hallmarks of the T2SL that other material platforms are lacking. In this paper, we discuss advantages of the T2SL, specifically the M-structure T2SL, which incorporates AlSb in the traditional InAs/GaSb superlattice. Using the M-structure, we present a new unipolar minority electron detector coined as the p-M-p, the letters which describe the composition of the device. Demonstration of this device structure with a 14 μm cutoff attained a detectivity of 4x1010 Jones (-50 mV) at 77 K. As device performance improves year after year with novel design contributions from the many researchers in this field, the natural progression in further enabling the ubiquitous use of this technology is to reduce cost and support the fabrication of large infrared imagers. In this paper, we also discuss the use of GaAs substrates as an enabling technology for third generation imaging on T2SLs. Despite the 7.8% lattice mismatch between the native GaSb and alternative GaAs substrates, T2SL photodiodes grown on GaAs at the MWIR and LWIR have been demonstrated at an operating temperature of 77 K [reprint (PDF)]
 
1.  Stranski-Krastanov growth of InGaN quantum dots emitting in green spectra
C. Bayram and M. Razeghi
Applied Physics A: Materials Science and Processing, Vol. 96, No. 2, p. 403-408-- August 1, 2009 ...[Visit Journal]
Self-assembled InGaN quantum dots (QDs) were grown on GaN templates by metalorganic chemical vapor deposition. 2D–3D growth mode transition through Stranski–Krastanov mode was observed via atomic force microscopy. The critical thickness for In0.67Ga0.33N QDs was determined to be four monolayers. The effects of growth temperature, deposition thickness, and V/III ratio on QD formation were examined. The capping of InGaN QDs with GaN was analyzed. Optimized InGaN quantum dots emitted in green spectra at room temperature. [reprint (PDF)]
 
1.  AlxGa1-xN Materials and Device Technology for Solar Blind Ultraviolet Photodetector Applications
R. McClintock, P. Sandvik, K. Mi, F. Shahedipour, A. Yasan, C. Jelen, P. Kung, and M. Razeghi
SPIE Conference, San Jose, CA, Vol. 4288, pp. 219-- January 22, 2001 ...[Visit Journal]
There has been a growing interest for the development of solar blind ultraviolet (UV) photodetectors for use in a variety of applications, including early missile threat warning, flame monitoring, UV radiation monitoring and chemical/biological reagent detection. The AlxGa1-xN material system has emerged as the most promising approach for such devices. However, the control of the material quality and the device technology are still rather immature. We report here the metalorganic chemical vapor deposition, the n-type and the p-type doping of high quality AlxGa1-xN thin films on sapphire substrates over a wide range of Al concentration. [reprint (PDF)]
 
1.  Cavity Length Effects of High-Temperature High-Power Continuous Wave Characteristics in Quantum-Cascade Lasers
J.S. Yu, A. Evans, J. David, L. Doris, S. Slivken, and M. Razeghi
Applied Physics Letters, 83 (25)-- December 22, 2003 ...[Visit Journal]
We report the cavity-length dependent high-temperature high-power cw characteristics in λ=6 µm quantum-cascade lasers with a thick electroplated Au top contact layer. For a high-reflectivity (HR) coated 15 µm wide and 3 mm long laser, the cw operation is achieved up to 313 K (40 °C) with an output power of 17 mW. At 298 K, a very high cw output power of 213 mW is obtained for a HR coated 15 µm wide and 4 mm long laser. Thermal resistance is analyzed at temperatures above 283 K for HR coated lasers with different cavities. [reprint (PDF)]
 
1.  Characteristics of high quality p-type AlxGa1-xN/GaN superlattices
A. Yasan, R. McClintock, S.R. Darvish, Z. Lin, K. Mi, P. Kung, and M. Razeghi
Applied Physics Letters 80 (12)-- March 18, 2002 ...[Visit Journal]
Very-high-quality p-type AlxGa1–xN/GaN superlattices have been grown by low-pressure metalorganic vapor-phase epitaxy through optimization of Mg flow and the period of the superlattice. For the superlattice with x = 26%, the hole concentration reaches a high value of 4.2×1018 cm–3 with a resistivity as low as 0.19 Ω · cm by Hall measurement. Measurements confirm that superlattices with a larger period and higher Al composition have higher hole concentration and lower resistivity, as predicted by theory. [reprint (PDF)]
 
1.  Widely tuned room temperature terahertz quantum cascade laser sources
Q.Y. Lu, N. Bandyopadhyay, S. Slivken, Y. Bai and M. Razeghi
SPIE Proceedings, Vol. 8631, p. 863108-1, Photonics West, San Francisco, CA-- February 3, 2013 ...[Visit Journal]
Room temperature THz quantum cascade laser sources with a broad spectral coverage based on intracavity difference frequency generation are demonstrated. Two mid-infrared active cores in the longer mid-IR wavelength range (9-11 micron)based on the single-phonon resonance scheme are designed with a second-order difference frequency nonlinearity specially optimized for the high operating fields that correspond to the highest mid-infrared output powers. A Čerenkov phase-matching scheme along with integrated dual-period distributed feedback gratings are used for efficient THz extraction and spectral purification. Single mode emissions from 1.0 to 4.6 THz with a side-mode suppression ratio and output power up to 40 dB and 32 μW are obtained, respectively. [reprint (PDF)]
 
1.  Amorphous ZnO films grown by room temperature pulsed laser deposition on paper and mylar for transparent electronics applications
D.J. Rogers, V.E. Sandana, F. Hosseini Teherani, R. McClintock, M. Razeghi, and H.J. Drouhin
SPIE Proceedings, San Francisco, CA (January 22-27, 2011), Vol. 7940, p. 79401K-- January 24, 2011 ...[Visit Journal]
Recently, there has been a surge of activity in the development of next-generation transparent thin film transistors for use in applications such as electronic paper and flexible organic light emitting diode panels. Amongst the transparent conducting oxides attracting the most interest at present are Amorphous Oxide Semiconductors (AOS) based on ZnO because they exhibit enhanced electron mobility (μ), superior capacity for processability in air and improved thermodynamic stability compared with conventional covalent amorphous semiconductors and existing AOS. Moreover, they give excellent performance when fabricated at relatively low temperature and can readily be made in large area format. Thus, they are projected to resolve the trade-off between processing temperature and device performance and thereby allow fabrication on inexpensive heatsensitive substrates. For the moment, however, an undesireable post-deposition annealing step at a temperature of about 200ºC is necessary in order to obtain suitable electrical and optical properties. This paper demonstrates the possibility of directly engineering amorphous ZnO with relatively high conductiviy at room temperature on paper and mylar substrates using pulsed laser deposition. [reprint (PDF)]
 
1.  Room temperature single-mode terahertz sources based on intracavity difference-frequency generation in quantum cascade lasers
Q.Y. Lu, N. Bandyopadhyay, S. Slivken, Y. Bai and M. Razeghi
Applied Physics Letters, Vol. 99, Issue 13, p. 131106-1-- September 26, 2011 ...[Visit Journal]
We demonstrate room temperature single-mode THz emission at 4 THz based on intracavity difference-frequency generation from mid-infrared dual-wavelength quantum cascade lasers. An integrated dual-period distributed feedback grating is defined on the cap layer to purify both mid-infrared pumping wavelengths and in turn the THz spectra. Single mode operation of the pumping wavelengths results in a single-mode THz operation with a narrow linewidth of 6.6 GHz. A maximum THz power of 8.5 μW with a power conversion efficiency of 10 μW/W² is obtained at room temperature. [reprint (PDF)]
 
1.  Development of Quantum Cascade Lasers for High Peak Output Power and Low Threshold Current Density
S. Slivken and M. Razeghi
Solid State Electronics 46-- January 1, 2002 ...[Visit Journal]
Design and material optimization are used to both decrease the threshold current density and increase the output power for quantum cascade lasers. Waveguides are designed to try and minimize free-carrier and surface-plasmon absorption. Excellent material characterization is also presented, showing excellent control over layer thickness, interface quality, and doping level. Experiments are done to both optimize the injector doping level and to maximize the output power from a single aperture. At 300 K, a threshold current density as low as 1.8 kA/cm² is reported, along with peak powers of approximately 2.5 W. Strain-balanced lasers are also demonstrated at λnot, vert, similar5 μm, exhibiting threshold current densities<300 A/cm² at 80 K. These values represent the state-of-the-art for mid-infrared lasers with λ>4 μm [reprint (PDF)]
 
1.  Back-illuminated separate absorption and multiplication GaN avalanche photodiodes
J.L. Pau, C. Bayram, R. McClintock, M. Razeghi and D. Silversmith
Applied Physics Letters, Vol. 92, No. 10, p. 101120-1-- March 10, 2008 ...[Visit Journal]
The performance of back-illuminated avalanche photodiodes with separate absorption and multiplication regions is presented. Devices with an active area of 225 µm2 show a maximum multiplication gain of 41,200. The calculation of the noise equivalent power yields a minimum value of 3.3×10−14 W·Hz−1/2 at a gain of 3000, increasing to 2.0×10−13 W·Hz−1/2 at a gain of 41,200. The broadening of the response edge has been analyzed as a function of bias. [reprint (PDF)]
 
1.  Type-II InAs/GaSb Superlattices and Detectors with Cutoff Wavelength Greater Than 18 μm
M. Razeghi, Y. Wei, A. Gin, G.J. Brown and D. Johnstone
Proceedings of the SPIE, San Jose, CA, Vol. 4650, 111 (2002)-- January 25, 2002 ...[Visit Journal]
The authors report the most recent advances in Type-II InAs/GaSb superlattice materials and photovoltaic detectors. Lattice mismatch between the substrate and the superlattice has been routinely achieved below 0.1%, and less than 0.0043% as the record. The FWHM of the zeroth order peak from x-ray diffraction has been decreased below 50 arcsec and a record of less than 44arcsec has been achieved. High performance detectors with 50% cutoff beyond 18 micrometers up to 26 micrometers have been successfully demonstrated. The detectors with a 50% cut-off wavelength of 18.8 micrometers showed a peak current responsivity of 4 A/W at 80K, and a peak detectivity of 4.510 cm·Hz½·W-1 was achieved at 80K at a reverse bias of 110 mV under 300 K 2(pi) FOV background. Some detectors showed a projected 0% cutoff wavelength up to 28~30 micrometers . The peak responsivity of 3Amp/Watt and detectivity of 4.2510 cm·Hz½·W-1 was achieved under -40mV reverse bias at 34K for these detectors. [reprint (PDF)]
 
1.  Recent Advances in Room Temperature, High-Power Terahertz Quantum Cascade Laser Sources Based on Difference-Frequency Generation
Quanyong Lu and Manijeh Razeghi
Photonics, 3, 42-- July 7, 2016 ...[Visit Journal]
We present the current status of high-performance, compact, THz sources based on intracavity nonlinear frequency generation in mid-infrared quantum cascade lasers. Significant performance improvements of our THz sources in the power and wall plug efficiency are achieved by systematic optimizing the device’s active region, waveguide, and chip bonding strategy. High THz power up to 1.9 mW and 0.014 mW for pulsed mode and continuous wave operations at room temperature are demonstrated, respectively. Even higher power and efficiency are envisioned based on enhancements in outcoupling efficiency and mid-IR performance. Our compact THz device with high power and wide tuning range is highly suitable for imaging, sensing, spectroscopy, medical diagnosis, and many other applications. [reprint (PDF)]
 
1.  Short Wavelength Solar-Blind Detectors: Status, Prospects, and Markets
M. Razeghi
IEEE Proceedings, Wide Bandgap Semiconductor Devices: The Third Generation Semiconductor Comes of Age 90 (6)-- June 1, 2002 ...[Visit Journal]
Recent advances in the research work on III-nitride semiconductors and AlxGa1-xN materials in particular has renewed the interest and led to significant progress in the development of ultraviolet (UV) photodetectors able to detect light in the mid- and near-UV spectral region (λ∼200-400 nm). There have been a growing number of applications which require the use of such sensors and, in many of these, it is important to be able to sense UV light without detecting infrared or visible light, especially from the Sun, in order to minimize the chances of false detection or high background. The research work on short-wavelength UV detectors has, therefore, been recently focused on realizing short-wavelength "solar-blind" detectors which, by definition, are insensitive to photons with wavelengths longer than ∼285 nm. In this paper the development of AlxGa1-xN-based solar-blind UV detectors will be reviewed. The technological issues pertaining to material synthesis and device fabrication will be discussed. The current state-of-the-art and future prospects for these detectors will be reviewed and discussed. [reprint (PDF)]
 
1.  Highly Conductive Co-Doped Ga2O3Si-In Grown by MOCVD
Junhee Lee, Honghyuk Kim, Lakshay Gautam and Manijeh Razeghi
Coatings 2021, 11(3), 287; https://doi.org/10.3390/coatings11030287 ...[Visit Journal]
We report a highly conductive gallium oxide doped with both silicon and indium grown on c-plane sapphire substrate by MOCVD. From a superlattice structure of indium oxide and gallium oxide doped with silicon, we obtained a highly conductive material with an electron hall mobility up to 150 cm2/V·s with the carrier concentration near 2 × 1017 cm−3. However, if not doped with silicon, both Ga2O3:In and Ga2O3 are highly resistive. Optical and structural characterization techniques such as X-ray, transmission electron microscope, and photoluminescence, reveal no significant incorporation of indium into the superlattice materials, which suggests the indium plays a role of a surfactant passivating electron trapping defect levels. [reprint (PDF)]
 
1.  Advanced InAs/GaSb Superlattice Photovoltaic Detectors for Very-Long Wavelength Infrared Applications
Y. Wei, A. Gin, M. Razeghi, and G.J. Brown
Applied Physics Letters 80 (18)-- May 6, 2002 ...[Visit Journal]
We report on the temperature dependence of the photoresponse of very long wavelength infrared type-II InAs/GaSb superlattice based photovoltaic detectors grown by molecular-beam epitaxy. The detectors had a 50% cutoff wavelength of 18.8 μm and a peak current responsivity of 4 A·W-1 at 80 K. A peak detectivity of 4.5×1010 cm· Hz½·W-1 was achieved at 80 K at a reverse bias of 110 mV. The generation–recombination lifetime was 0.4 ns at 80 K. The cutoff wavelength increased very slowly with increasing temperature with a net shift from 20 to 80 K of only 1.2 μm [reprint (PDF)]
 
1.  Comparison of ZnO nanostructures grown using pulsed laser deposition, metal organic chemical vapor deposition, and physical vapor transport
V.E. Sandana, D.J. Rogers, F. Hosseini Teherani, R. McClintock, C. Bayram, M. Razeghi, H-J Drouhin, M.C. Clochard, V. Sallett, G. Garry, and F. Falyouni
Journal of Vacuum Science and Technology B, Vol. 27, No. 3, May/June, p. 1678-1683-- May 29, 2009 ...[Visit Journal]
This article compares the forms and properties of ZnO nanostructures grown on Si (111) and c-plane sapphire (c-Al2O3) substrates using three different growth processes: metal organic chemical vapor deposition (MOCVD), pulsed laser deposition (PLD), and physical vapor transport (PVT). A very wide range of ZnO nanostructures was observed, including nanorods, nanoneedles, nanocombs, and some novel structures resembelling “bevelled” nanowires. PVT gave the widest family of nanostructures. PLD gave dense regular arrays of nanorods with a preferred orientation perpendicular to the substrate plane on both Si and c-Al2O3 substrates, without the use of a catalyst. X-ray diffraction (XRD) studies confirmed that nanostructures grown by PLD were better crystallized and more highly oriented than those grown by PVT and MOCVD. Samples grown on Si showed relatively poor XRD response but lower wavelength emission and narrower linewidths in PL studies. [reprint (PDF)]
 
1.  Band-gap narrowing and potential fluctuation in Si-doped GaN
I.H. Lee, J.J. Lee, P. Kung, F.J. Sanchez, and M. Razeghi
Applied Physics Letters 74 (1)-- January 4, 1999 ...[Visit Journal]
We investigate the optical properties of two sets of Si-doped GaN epitaxial layers with different degree of compensation. The electron concentration dependence of the band-gap energy measured by photoluminescence is interpreted as band-gap narrowing effect and evaluated by a simple relation. The photoluminescence peak positions of heavily compensated samples are shifted downward with respect to those of moderately compensated samples, and the down shift becomes larger at higher electron density. Based on analysis of photoluminescence spectra, these prominent behaviors are accounted for by band-edge potential fluctuation associated with inhomogeneous residual impurities. [reprint (PDF)]
 
1.  Responsivity and Noise Performance of InGaAs/InP Quantum Well Infrared Photodetectors
C. Jelen, S. Slivken, T. David, G. Brown, and M. Razeghi
SPIE Conference, San Jose, CA, -- January 28, 1998 ...[Visit Journal]
Dark current nose measurements were carried out between 10 and 104 Hz at T = 80K on two InGaAs/InP quantum well IR photo detectors (QWIPs) designed for 8 μm IR detection. Using the measured noise data, we have calculated the thermal generation rate, bias-dependent gain, electron trapping probability, and electron diffusion length. The calculated thermal generation rate is similar to AlGaAs/GaAs QWIPs with similar peak wavelengths, but the gain is 50X larger, indicating improved transport and carrier lifetime are obtained in the binary InP barriers. As a result, a large responsivity of 7.5 A/W at 5V bias and detectivity of 5 X 1011 cm·Hz½/W at 1.2 V bias were measured for the InGaAs/InP QWIPs at T = 80K. [reprint (PDF)]
 
1.  280 nm UV LEDs Grown on HVPE GaN Substrates
A. Yasan, R. McClintock, K. Mayes, S.R. Darvish, P. Kung, M. Razeghi, and R.J. Molnar
Opto-Electronics Review, 10 (4)-- January 1, 2002 ...[Visit Journal]
We report on the enhancement of optical and electrical properties of 280 nm UV LEDs using low dislocation density HVPE-grown GaN substrate. Compared with the same structure grown on sapphire, these LEDs show ~30% reduction in current-voltage differential resistance, ~15% reduction in turn-on voltage, more than 200% increase in output power slope efficiency and saturation at higher currents. Lower density of defects due to higher material quality and better heat dissipation are believed to be the reason behind these improvements. [reprint (PDF)]
 
1.  Widely tuned room temperature terahertz quantum cascade laser sources based on difference-frequency generation
Q.Y. Lu, N. Bandyopadhyay, S. Slivken, Y. Bai and M. Razeghi
Applied Physics Letters, Vol. 101, No. 25, p. 251121-1-- December 17, 2012 ...[Visit Journal]
We demonstrate room temperature THz quantum cascade laser sources with a broad spectral coverage based on intracavity difference-frequency generation. Two mid-infrared active cores based on the single-phonon resonance scheme are designed with a THz nonlinearity specially optimized at the high operating fields that correspond to the highest mid-infrared output powers. A Čerenkov phase-matching scheme along with integrated dual-period distributed feedback gratings are used for efficient THz extraction and spectral purification. Single mode emissions from 1.0 to 4.6 THz with a side-mode suppression ratio and output power up to 40 dB and 32 μW are obtained, respectively. [reprint (PDF)]
 
1.  Temperature dependent characteristics of λ ~ 3.8 µm room-temperature continuous-wave quantum-cascade lasers
J.S. Yu, A. Evans, S. Slivken, S.R. Darvish and M. Razeghi
Applied Physics Letters, 88 (25)-- June 19, 2006 ...[Visit Journal]
The highest-performance device displays pulsed laser action at wavelengths between 3.4 and 3.6 μm, for temperatures up to 300 K, with a low temperature (80 K) threshold current density of approximately 2.6 kA/cm2, and a characteristic temperature of T0~130 K. The shortest wavelength QCL (λ ~ 3.05 μm) has a higher threshold current density (~12 kA/cm2 at T=20 K) and operates in pulsed mode at temperatures up to 110 K. [reprint (PDF)]
 
1.  ZnO nanorod electrodes for hydrogen evolution and storage
Harinipriya, S.; Usmani, B.; Rogers, D. J.; Sandana, V. E.; Teherani, F. Hosseini; Lusson, A.; Bove, P.; Drouhin, H.-J.; Razeghi, M.
Proc. SPIE 8263, Oxide-based Materials and Devices III, 82631Y (February 9, 2012)-- February 9, 2012 ...[Visit Journal]
Due to the attractive combination of a relatively high specific heat of combustion with a large specific energy capacity, molecular hydrogen (H2) is being investigated for use as an alternative to fossil fuels. Energy-efficient H2 production and safe storage remain key technical obstacles to implementation of an H2 based economy, however. ZnO has been investigated for use as an alternative photocatalytic electrode to TiO2 for solarpowered photo-electro-chemical (PEC) electrolysis, in which H2 is generated by direct water splitting in a cell with a metal cathode and a semiconducting anode. In this investigation, ZnO NR grown on Si (100) substrates by pulsed laser deposition were investigated for use as electrodes in the Hydrogen Evolution Reaction (HER). The electrochemical potential and Fermi energy of the ZnO NR were estimated from the electrochemical current density in acid and alkaline solutions via phenomenological thermodynamic analysis. As well as acting as an effective electrocalytic cathode, the ZnO NR appear to operate as a hydrogen reservoir. These results indicate that the ZnO NR have excellent potential for the storage of evolved H2. [reprint (PDF)]
 
1.  Optical Investigations of GaAs-GaInP Quantum Wells Grown on the GaAs, InP, and Si Substrates
H. Xiaoguang, M. Razeghi
Applied Physics Letters 61 (14)-- October 5, 1992 ...[Visit Journal]
We report the first photoluminescence investigation of GaAs‐Ga0.51In0.49P lattice matched multiquantum wells grown by the low pressure metalorganic chemical vapor deposition simultaneously in the same run on GaAs, Si, and InP substrates. The sharp photoluminescence peaks indicate the high quality of the samples on three different substrates. The temperature dependence of the photoluminescence indicates that the intrinsic excitonic transitions dominate at low temperature and free‐carrier recombinations at room temperature. The photoluminescence peaks of the samples grown on Si and InP substrates shift about 15 meV from the corresponding peaks of the sample grown on the GaAs substrate. Two possible interpretations are provided for the observed energy shift. One is the diffusion of In along the dislocation threads from GaInP to GaAs and another is the localized strain induced by defects and In segregations. [reprint (PDF)]
 

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