Page 18 of 22:  Prev << 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18  19 20 21 22  >> Next  (547 Items)

1.  TEG IN LP-MO CVD Ga 0 4 7 ln 0 S3 As-lnP SUPERLATTICE
M. RAZEGHIM. A. POISSONJ. P. LARIVAINB. de CREMOUXJ. P. DUCHEMIN
ELECTRONICS LETTERs, 1982 ,Vol. 18-- April 15, 1982 ...[Visit Journal]
We report the first successful growth of Ga o .4. 7 In 0 . J3 As-InPsuperlattice by the low-pressure metalorganic chemicalvapour deposition technique, and evidence for TEG proper-ties in these structures. [reprint (PDF)]
 
1.  Low irradiance background limited type-II superlattice MWIR M-barrier imager
E.K. Huang, S. Abdollahi Pour, M.A. Hoang, A. Haddadi, M. Razeghi and M.Z. Tidrow
OSA Optics Letters (OL), Vol. 37, No. 11, p. 2025-2027-- June 1, 2012 ...[Visit Journal]
We report a type-II superlattice mid-wave infrared 320 × 256 imager at 81 K with the M-barrier design that achieved background limited performance (BLIP) and ∼99%operability. The 280 K blackbody’s photon irradiance was limited by an aperture and a band-pass filter from 3.6 μm to 3.8 μm resulting in a total flux of ∼5 × 1012 ph·cm−2·s−1. Under these low-light conditions, and consequently the use of a 13.5 ms integration time, the imager was observed to be BLIP thanks to a ∼5 pA dark current from the 27 μm wide pixels. The total noise was dominated by the photon flux and read-out circuit which gave the imager a noise equivalent input of ∼5 × 1010 ph·cm−2·s−1 and temperature sensitivity of 9 mK with F∕2.3 optics. Excellent imagery obtained using a 1-point correction alludes to the array’s uniform responsivity. [reprint (PDF)]
 
1.  Background limited performance of long wavelength infrared focal plane arrays fabricated from M-structure InAs-GaSb superlattices
P.Y. Delaunay, B.M. Nguyen, D. Hoffman, E.K. Huang, and M. Razeghi
IEEE Journal of Quantum Electronics, Vol. 45, No. 2, p. 157-162.-- February 1, 2009 ...[Visit Journal]
The recent introduction of a M-structure design improved both the dark current and R0A performances of Type-II InAs-GaSb photodiodes. A focal plane array fabricated with this design was characterized at 81 K. The dark current of individual pixels was measured between 1.1 and 1.6 nA, 7 times lower than previous superlattice FPAs. This led to a higher dynamic range and longer integration times. The quantum efficiency of detectors without antireflective coating was 74%. The noise equivalent temperature difference reached 23 mK, limited only by the performance of the testing system and the read out integrated circuit. Background limited performances were demonstrated at 81 K for a 300 K background. [reprint (PDF)]
 
1.  Gain and recombination dynamics in photodetectors made with quantum nanostructures: The quantum dot in a well and the quantum well
B. Movaghar, S. Tsao, S. Abdollahi Pour, T. Yamanaka, and M. Razeghi
Physical Review B, Vol. 78, No. 11-- September 15, 2008 ...[Visit Journal]
We consider the problem of charge transport and recombination in semiconductor quantum well infrared photodetectors and quantum-dot-in-a-well infrared detectors. The photoexcited carrier relaxation is calculated using rigorous random-walk and diffusion methods, which take into account the finiteness of recombination cross sections, and if necessary the memory of the carrier generation point. In the present application, bias fields are high and it is sufficient to consider the drift limited regime. The photoconductive gain is discussed in a quantum-mechanical language, making it more transparent, especially with regard to understanding the bias and temperature dependence. Comparing experiment and theory, we can estimate the respective recombination times. The method developed here applies equally well to nanopillar structures, provided account is taken of changes in mobility and trapping. Finally, we also derive formulas for the photocurrent time decays, which in a clean system at high bias are sums of two exponentials. [reprint (PDF)]
 
1.  Non-equilibrium radiation of long wavelength InAs/GaSb superlattice photodiodes
D. Hoffman, A. Hood, F. Fuchs and M. Razeghi
Journal of Applied Physics 99-- February 15, 2006 ...[Visit Journal]
The emission behavior of binary-binary type-II InAs/GaSb superlattice photodiodes has been studied in the spectral range between 8 and 13 μm. With a radiometric calibration of the experimental setup the internal and external quantum efficiencies have been determined in the temperature range between 80 and 300 K for both the negative and positive luminescences. [reprint (PDF)]
 
1.  Dark current reduction in microjunction-based compound electron barrier type-II InAs/InAs1-xSbx superlattice-based long-wavelength infrared photodetectors
Romain Chevallier, Abbas Haddadi, Manijeh Razeghi
Proc. SPIE 10540, Quantum Sensing and Nano Electronics and Photonics XV Page. 1054007-1-- January 26, 2018 ...[Visit Journal]
Reduction of dark current density in microjunction-based InAs/InAs1-xSbx type-II superlattice long-wavelength infrared photodetectors was demonstrated. A double electron barrier design was used to suppress both generation-recombination and surface dark currents. The photodetectors exhibited high surface resistivity after passivation with SiO2, which permits the use of small size features without having strong surface leakage current degrading the electrical performance. Fabricating a microjunction structure (25×25 μm² mesas with 10×10 μm² microjunctions) with this photodetector double barrier design results in a dark current density of 6.3×10-6 A/cm² at 77 K. The device has an 8 μm cut-off wavelength at 77 K and exhibits a quantum efficiency of 31% for a 2 μm-thick absorption region, which results in a specific detectivity value of 1.2×1012 cm·Hz1/2/W at 77 K. [reprint (PDF)]
 
1.  Beryllium compensation doping of InAs/GaSb infrared superlattice photodiodes
D. Hoffman, B.M. Nguyen, P.Y. Delaunay, A. Hood, M. Razeghi and J. Pellegrino
Applied Physics Letters, Vol. 91, No. 14, p. 143507-1-- October 1, 2007 ...[Visit Journal]
Capacitance-voltage measurements in conjunction with dark current measurements on InAs/GaSb long wavelength infrared superlattice photodiodes grown by molecular-beam epitaxy on GaSb substrates are reported. By varying the beryllium concentration in the InAs layer of the active region, the residually n-type superlattice is compensated to become slightly p-type. By adjusting the doping, the dominant dark current mechanism can be varied from diffusion to Zener tunneling. Minimization of the dark current leads to an increase of the zero-bias differential resistance from less than 4 to 32 cm2 for a 100% cutoff of 12.05 µm [reprint (PDF)]
 
1.  High Power 0.98 μm GaInAs/GaAs/GaInP Multiple Quantum Well Laser
K. Mobarhan, M. Razeghi, G. Marquebielle and E. Vassilaki
Journal of Applied Physics 72 (9)-- November 1, 1992 ...[Visit Journal]
We report the fabrication of high quality Ga0.8In0.2As/GaAs/Ga0.51In0.49P multiple quantum well laser emitting at 0.98 μm grown by low pressure metalorganic chemical vapor deposition. Continuous wave operation with output power of 500 mW per facet was achieved at room temperature for a broad area laser with 130 μm width and 300 μm cavity length. This is an unusually high value of output power for this wavelength laser in this material system. The differential quantum efficiency exceeded 75% with excellent homogeneity and uniformity. The characteristic temperature, T0 was in the range of 120–130 K. [reprint (PDF)]
 
1.  Spatial Noise and Correctability of Type-II InAs/GaSb Focal Plane Arrays
P.Y. Delaunay and M. Razeghi
IEEE Journal of Quanutm Electronics, April 2010, Vol. 46, No. 4, p. 584-588-- April 1, 2010 ...[Visit Journal]
A long wavelength infrared focal plane array based on Type-II InAs/GaSb superlattices was fabricated and characterized at 80 K. The noise equivalent temperature difference of the array was measured as low as 23 mK (f# = 2), for an integration time of 0.129 ms. The spatial noise of the array was dominated by the nonuniformity of the illumination through the circular aperture. A standard two-point nonuniformity correction improved the inhomogeneity equivalent temperature difference to 16 mK. The correctability just after calibration was 0.6. The long-term stability time was superior to 25 hours. [reprint (PDF)]
 
1.  Performance characteristics of high-purity mid-wave and long-wave infrared type-II InAs/GaSb superlattice infrared photodiodes
A. Hood, M. Razeghi, V. Nathan and M.Z. Tidrow
SPIE Conference, San Jose, CA, Vol. 6127, pp. 61270U-- January 23, 2006 ...[Visit Journal]
The authors report on recent advances in the development of mid-, long-, and very long-wavelength infrared (MWIR, LWIR, and VLWIR) Type-II InAs/GaSb superlattice infrared photodiodes. The residual carrier background of binary Type-II InAs/GaSb superlattice photodiodes of cut-off wavelengths around 5 µm has been studied in the temperature range between 10 and 200 K. A four-point, capacitance-voltage technique on mid-wavelength and long-wavelength Type-II InAs/GaSb superlattice infrared photodiodes reveal residual background concentrations around 5×1014 cm-3. Additionally, recent progress towards LWIR photodiodes for focal plane array imaging applications is presented. [reprint (PDF)]
 
1.  Surface leakage current reduction in long wavelength infrared type-II InAs/GaSb superlattice photodiodes
S. Bogdanov, B.M. Nguyen, A.M. Hoang, and M. Razeghi
Applied Physics Letters, Vol. 98, No. 18, p. 183501-1-- May 2, 2011 ...[Visit Journal]
Dielectric passivation of long wavelength infrared Type-II InAs/GaSb superlattice photodetectors with different active region doping profiles has been studied. SiO2 passivation was shown to be efficient as long as it was not put in direct contact with the highly doped superlattice. A hybrid graded doping profile combined with the shallow etch technique reduced the surface leakage current in SiO2 passivated devices by up to two orders of magnitude compared to the usual design. As a result, at 77 K the SiO(2) passivated devices with 10.5 μm cutoff wavelength exhibit an R0A of 120 Ω·cm², RmaxA of 6000 Ω·cm², and a dark current level of 3.5×10−5 A·cm−2 at −50 mV bias. [reprint (PDF)]
 
1.  Negative and positive luminescence in mid-wavelength infrared InAs/GaSb superlattice photodiodes
D. Hoffman, A. Gin, Y. Wei, A. Hood, F. Fuchs, and M. Razeghi
IEEE Journal of Quantum Electronics, 41 (12)-- December 1, 2005 ...[Visit Journal]
The quantum efficiency of negative and positive luminescence in binary type-II InAs-GaSb superlattice photodiodes has been investigated in the midinfrared spectral range around the 5-μm wavelength. The negative luminescence efficiency is nearly independent on temperature in the entire range from 220 to 325 K. For infrared diodes with a 2-μm absorbing layer, processed without anti-reflection coating, a negative luminescence efficiency of 45% is found, indicating very efficient minority carrier extraction. The temperature dependent measurements of the quantum efficiency of the positive luminescence enables for the determination of the capture cross section of the Shockley-Read-Hall centers involved in the competing nonradiative recombination. [reprint (PDF)]
 
1.  Investigation of surface leakage reduction for small pitch shortwave infrared photodetectors
Arash Dehzangi, Quentin Durlin, Donghai Wu, Ryan McClintock, Manijeh Razeghi
Semiconductor Science and Technology, 34(6), 06LT01-- May 25, 2019 ...[Visit Journal]
Different passivation techniques are investigated for reducing leakage current in small pixel (down to 9 μm) heterostructure photodetectors designed for the short-wavelength infrared range. Process evaluation test chips were fabricated using the same process as for focal plane arrays. Arrays of small photodetectors were electrically characterized under dark conditions from 150 K to room temperature. In order to evaluate the leakage current, we studied the relation between the inverse of dynamic resistance at −20 mV and zero bias and perimeter over area P/A ratio as the pixel size is scaled down. At 150 K, leakage current arising from the perimeter dominates while bulk leakage dominates at room temperature. We find that in shortwave devices directly underfilling hybridized devices with a thermoset epoxy resin without first doing any additional passivation/protection after etching gives the lowest leakage with a surface resistance of 4.2 × 109 and 8.9 × 103 Ω· cm−1 at 150 and 300 K, for −20 mV of bias voltage, respectively. [reprint (PDF)]
 
1.  Efficiency of photoluminescence and excess carrier confinement in InGaAsP/GaAs structures prepared by metal-organic chemical vapor deposition
J. Diaz, H.J. Yi, M. Erdtmann, X. He, E. Kolev, D. Garbuzov, E. Bigan, and M. Razeghi
Journal of Applied Physics 76 (2)-- July 15, 1994 ...[Visit Journal]
Special double‐ and separate‐confinement InGaAsP/GaAs heterostructures intended for photoluminescence measurements have been grown by low‐pressure metal‐organic chemical‐vapor deposition. The band gap of the active region quaternary material was close to 1.5 eV, and the waveguide of the separate‐confinement structures was near 1.8 eV. Measurement of the integrated luminescence efficiency at 300 K has shown that over a wide range of excitation level (10–103 W/cm²) radiative transitions are the dominant mechanism for excess carrier recombination in the active region of the structures studied. As determined by spectral measurements, the excess carrier concentration in the waveguide of the separate‐confinement heterostructures and the intensity of the waveguide emission band correspond to a condition of thermal equilibrium of the excess carrier populations in the active region and the waveguide. The ratio of the intensity of the waveguide emission to the active region emission fits a model which assumes that the barrier height for minority carriers (holes) is equal to the difference in band gaps between the active region and the waveguide region. [reprint (PDF)]
 
1.  8-13 μm InAsSb heterojunction photodiode operating at near room temperature
J.D. Kim, S. Kim, D. Wu, J. Wojkowski, J. Xu, J. Piotrowski, E. Bigan, and M. Razeghi
Applied Physics Letters 67 (18)-- October 30, 1995 ...[Visit Journal]
p+-InSb/π-InAs1−xSbx/n+-InSb heterojunction photodiodes operating at near room temperature in the 8–13 μm region of infrared (IR) spectrum are reported. A room‐temperature photovoltaic response of up to 13 μm has been observed at 300 K with an x≊0.85 sample. The voltage responsivity‐area product of 3×10−5 V· cm²/W has been obtained at 300 K for the λ=10.6 μm optimized device. This was close to the theoretical limit set by the Auger mechanism, with a detectivity at room temperature of ≊1.5×108 cm ·Hz½/W. [reprint (PDF)]
 
1.  Type-II superlattice-based extended short-wavelength infrared focal plane array with an AlAsSb/GaSb superlattice etch-stop layer to allow near-visible light detection
Romain Chevallier, Arash Dehzangi, Abbas Haddadi, and Manijeh Razeghi
Optics Letters Vol. 42, Iss. 21, pp. 4299-4302-- October 17, 2017 ...[Visit Journal]
A versatile infrared imager capable of imaging the near-visible to the extended short-wavelength infrared (e-SWIR) is demonstrated using e-SWIR InAs/GaSb/AlSb type-II superlattice-based photodiodes. A bi-layer etch-stop scheme consisting of bulk InAs0.91Sb0.09 and AlAs0.1Sb0.9/GaSb superlattice layers is introduced for substrate removal from the hybridized back-side illuminated photodetectors. The implementation of this new technique on an e-SWIR focal plane array results in a significant enhancement in the external quantum efficiency (QE) in the 1.8–0.8μm spectral region, while maintaining a high QE at wavelengths longer than 1.8μm. Test pixels exhibit 100% cutoff wavelengths of ∼2.1 and ∼2.25μm at 150 and 300K, respectively. They achieve saturated QE values of 56% and 68% at 150 and 300K, respectively, under back-side illumination and without any anti-reflection coating. At 150K, the photodetectors (27μm×27μm area) exhibit a dark current density of 4.7×10−7  A/cm2 under a −50  mV applied bias providing a specific detectivity of 1.77×1012  cm·Hz1/2/W. At 300K, the dark current density reaches 6.6×10−2  A/cm2 under −50 mV bias, providing a specific detectivity of 5.17×109  cm·Hz1/2/W. [reprint (PDF)]
 
1.  High performance InAs quantum dot infrared photodetectors (QDIP) on InP by MOCVD
W. Zhang, H. Lim, M. Taguchi, S. Tsao, J. Szafraniec, B. Movaghar, M. Razeghi, and M. Tidrow
SPIE Conference, Jose, CA, Vol. 5732, pp. 326-- January 22, 2005 ...[Visit Journal]
Inter-subband detectors such as quantum well infrared photodetectors (QWIP) have been widely used in infrared detection. Quantum dot infrared photodetectors (QDIPs) have been predicted to have better performance than QWIPs including higher operation temperature and normal incidence detection. Here we report our recent results of InAs QDIP grown on InP substrate by low-pressure metalorganic chemical vapor deposition (MOCVD). The device structures consist of multiple stacks of InAs quantum dots with InP barriers. High detectivities in the range of 1010cm·Hz1/2/W were obtained at 77K. The measurements at higher temperatures show better temperature dependent performance than QWIP. However, the performances of QDIPs are still far from the expected. One of the reasons is the low quantum efficiency due to the low fill factor of quantum dots layer. Resonant cavity enhanced QDIP has been studied to increase the quantum efficiency. Different schemes of mirrors using free carrier plasma and distributed Bragg reflector are discussed. [reprint (PDF)]
 
1.  Recent progress of widely tunable, CW THz sources based QCLs at room temperature
Manijeh Razeghi
Terahertz Science and Technology, Vol.10, No.4, pp. 87-151-- December 7, 2017 ...[Visit Journal]
The THz spectral region is of significant interest to the scientific community, but is one of the hardest regions to access with conventional technology. A wide range of compelling new applications are initiating a new revolution in THz technology, especially with regard to the development of compact and versatile devices for THz emission and detection. In this article, recent advances with regard to III-V semiconductor optoelectronics are explored with emphasis on how these advances will lead to the next generation of THz component technology [reprint (PDF)]
 
1.  Cubic Phase GaN on Nano-grooved Si (100) via Maskless Selective Area Epitaxy
Bayram, C., Ott, J. A., Shiu, K.-T., Cheng, C.-W., Zhu, Y., Kim, J., Razeghi, M. and Sadana, D. K.
Adv. Funct. Mater. 2014-- April 1, 2014 ...[Visit Journal]
A method of forming cubic phase (zinc blende) GaN (referred as c-GaN) on a CMOS-compatible on-axis Si (100) substrate is reported. Conventional GaN materials are hexagonal phase (wurtzite) (referred as h-GaN) and possess very high polarization fields (∼MV/cm) along the common growth direction of <0001>. Such large polarization fields lead to undesired shifts (e.g., wavelength and current) in the performance of photonic and vertical transport electronic devices. The cubic phase of GaN materials is polarization-free along the common growth direction of <001>, however, this phase is thermodynamically unstable, requiring low-temperature deposition conditions and unconventional substrates (e.g., GaAs). Here, novel nano-groove patterning and maskless selective area epitaxy processes are employed to integrate thermodynamically stable, stress-free, and low-defectivity c-GaN on CMOS-compatible on-axis Si. These results suggest that epitaxial growth conditions and nano-groove pattern parameters are critical to obtain such high quality c-GaN. InGaN/GaN multi-quantum-well structures grown on c-GaN/Si (100) show strong room temperature luminescence in the visible spectrum, promising visible emitter applications for this technology. [reprint (PDF)]
 
1.  A hybrid green light-emitting diode comprised of n-ZnO/(InGaN/GaN) multi-quantum-wells/p-GaN
C. Bayram, F. Hosseini Teherani, D.J. Rogers and M. Razeghi
Applied Physics Letters, Vol. 93, No. 8, p. 081111-1-- August 25, 2008 ...[Visit Journal]
Hybrid green light-emitting diodes (LEDs) comprised of n-ZnO/(InGaN/GaN) multi-quantum-wells/p-GaN were grown on semi-insulating AlN/sapphire using pulsed laser deposition for the n-ZnO and metal organic chemical vapor deposition for the other layers. X-ray diffraction revealed that high crystallographic quality was preserved after the n-ZnO growth. LEDs showed a turn-on voltage of 2.5 V and a room temperature electroluminescence (EL) centered at 510 nm. A blueshift and narrowing of the EL peak with increasing current was attributed to bandgap renormalization. The results indicate that hybrid LED structures could hold the prospect for the development of green LEDs with superior performance. [reprint (PDF)]
 
1.  Passivation of Type-II InAs/GaSb Superlattice Photodiodes
A. Gin, Y. Wei, J. Bae, A. Hood, J. Nah, and M. Razeghi
International Conference on Metallurgical Coatings and Thin Films (ICMCTF), San Diego, CA; Thin Solid Films 447-448-- January 30, 2004 ...[Visit Journal]
Recently, excellent infrared detectors have been demonstrated using Type-II InAs/GaSb superlattice materials sensitive at wavelengths from 3 μm to greater than 32 μm. These results indicate that Type-II superlattice devices may challenge the preponderance of HgCdTe and other state-of-the-art infrared material systems. As such, surface passivation is becoming an increasingly important issue as progress is made towards the commercialization of Type-II devices and focal plane array applications. This work focuses on initial attempts at surface passivation of Type-II InAs/GaSb superlattice photodiodes using PECVD-grown thin layers of SiO2. Our results indicate that silicon dioxide coatings deposited at various temperatures improve photodetector resistivity by several times. Furthermore, reverse-bias dark current has been reduced significantly in passivated devices. [reprint (PDF)]
 
1.  Resonant cavity enhanced heterojunction phototransistors based on type-II superlattices
Jiakai Li, Arash Dehzangi, Donghai Wu, Ryan McClintock, Manijeh Razeghi
Infrared Physics & Technology Available online 27 October 2020, 103552 https://doi.org/10.1016/j.infrared.2020.103552-- October 27, 2020 ...[Visit Journal]
Resonant cavity enhanced heterojunction phototransistor based on InAs/GaSb/AlSb type-II superlattice grown by molecular beam epitaxy has been demonstrated. The resonant wavelength was designed to be at near 1.9 μm wavelength range at room temperature. An eleven-pair lattice matched GaSb-AlAsSb quarter-wavelength Bragg reflector was used in the RCE-HPT to enhance the photoresponse. The device showed the wavelength selectivity and a cavity enhancement of the responsivity at 1.9 μm at room temperature. [reprint (PDF)]
 
1.  High power, continuous wave, quantum cascade ring laser
Y. Bai, S. Tsao, N. Bandyopadhyay, S. Slivken, Q.Y. Lu, D. Caffey, M. Pushkarsky, T. Day and M. Razeghi
Applied Physics Letters, Vol. 99, No. 26, p. 261104-1-- December 26, 2011 ...[Visit Journal]
We demonstrate a quantum cascade ring laser with high power room temperature continuous wave operation. A second order distributed feedback grating buried inside the waveguide provides both in-plane feedback and vertical power outcoupling. Total output power reaches 0.51 W at an emission wavelength around 4.85 μm. Single mode operation persists up to 0.4 W. The far field analysis indicates that the device operates in a high order mode. The magnetic and electric components of the ring-shaped lasing beam are in radial and azimuthal directions, respectively. [reprint (PDF)]
 
1.  Thermal stability of GaN thin films grown on (0001) Al2O3, (0112) Al2O3 and (0001)Si 6H-SiC substrates
C.J. Sun, P. Kung, A. Saxler, H. Ohsato, E. Bigan, M. Razeghi, and D.K. Gaskill
Journal of Applied Physics 76 (1)-- July 1, 1994 ...[Visit Journal]
Single crystals of GaN were grown on (0001), (0112) Al2O3 and (0001)Si 6H‐SiC substrates using an atmospheric pressure metalorganic chemical‐vapor‐deposition reactor. The relationship has been studied between the thermal stability of the GaN films and the substrate’s surface polarity. It appeared that the N‐terminated (0001) GaN surface grown on (0001)Si 6H‐SiC has the most stable surface, followed by the nonpolar (1120) GaN surface grown on (0112) Al2O3, while the Ga‐terminated (0001) GaN surface grown on (0001) Al2O3 has the least stable surface. This is explained with the difference in the atomic configuration of each of these surfaces which induces a difference in their thermal decomposition. [reprint (PDF)]
 
1.  Infrared Imaging Arrays Using Advanced III-V Materials and technology
M. Razeghi, J.D. Kim, C. Jelen, S. Slivken, E. Michel, H. Mohseni, J.J. Lee, J. Wojkowski, K.S. Kim, H.I. Jeon, and J. X
IEEE Proceedings, Advanced Workshop on Frontiers in Electronics (WOFE), Tenerife, Spain;-- January 6, 1997 ...[Visit Journal]
Photodetectors operating in the 3-5 and 8-12 μm atmospheric windows are of great importance for applications in infrared (IR) thermal imaging. HgCdTe has been the dominant material system for these applications. However, it suffers from instability and non-uniformity problems over large areas due to high Hg vapor pressure during the material, growth. There has been a lot of interest in the use of heteroepitaxially grown Sb-based alloys, its strained layer superlattices, and GaAs based quantum wells as alternatives to MCT. This interest has been driven by the advanced material growth and processing technology available for the III-V material system [reprint (PDF)]
 

Page 18 of 22:  Prev << 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18  19 20 21 22  >> Next  (547 Items)