Multi-Hundred Gigahertz Photodetector Development Using LT GaAs

1991 ◽  
Vol 241 ◽  
Author(s):  
Y. Chen ◽  
S. Williamson ◽  
T. Brock ◽  
F. W. Smith ◽  
A. R. Calawa
Keyword(s):  
Low Temperature ◽  
Light Intensity ◽  
Response Time ◽  
Bias Voltage ◽  
Type Detector ◽  
Low Temperature Grown Gaas ◽  
Lt Gaas

ABSTRACTWe report on the development of a new, integrable photoconductive-type detector based on low-temperature-grown GaAs. The detector has a response time of 1.2 ps and a 3-dB bandwidth of 375 GHz. The responsivity is 0.1 A/W. This is the fastest photodetector reported to date. We discuss the unique properties of this device, including its performance as functions of both light intensity and bias voltage.

Real-Time Pseudodielectric Function of Low-Temperature-Grown GaAs

2000 ◽  
Vol 618 ◽  
Author(s):  
D.A. Gajewski ◽  
J.E. Guyer ◽  
J.J. Kopanski ◽  
J.G. Pellegrino
Keyword(s):  
Low Temperature ◽  
Real Time ◽  
Diffuse Reflectance Spectroscopy ◽  
High Energy ◽  
Real Time Control ◽  
The Real ◽  
Time Control ◽  
Active Feedback ◽  
Low Temperature Grown Gaas ◽  
Lt Gaas

ABSTRACTWe present the real-time pseudodielectric function <ε(E)> of low-temperature-grown GaAs (LT-GaAs) thin films during the growth as a function of growth temperature Tg and thickness. We obtained accurate measurements of the real-time <εc(E)> by using in situspectroscopic ellipsometry (SE) in conjunction with active feedback control of the substrate temperature using diffuse reflectance spectroscopy. We show that for epitaxial LT-GaAs layers, the peak in the imaginary pseudodielectric function <ε2(E)> decreases in amplitude and sharpness systematically with decreasing Tg. We also revealed an abrupt change in <εc(E)> near the critical epitaxial thickness hepi, the value of which decreases with decreasing Tg. Above hepi, the LT-GaAs grows polycrystalline (amorphous) above (below) Tg ∼ 190°C. We also simultaneously monitored the surface roughness and crystallinity by using real-time reflection high-energy electron diffraction (RHEED). These results represent progress in obtaining real-time control over the composition and morphology of LT-GaAs

Spectroscopic Ellipsometric Characterization of Low Temperature GaAs

1995 ◽  
Vol 378 ◽  
Author(s):  
X. Gao ◽  
P. G. Snyder ◽  
P. W. Yu ◽  
Y. Q. Zhang ◽  
Z. F. Peng
Keyword(s):  
Low Temperature ◽  
Red Shift ◽  
Strain Effect ◽  
Lorentz Oscillator ◽  
Ellipsometric Characterization ◽  
C 30 ◽  
Low Temperature Gaas ◽  
Low Temperature Grown Gaas ◽  
Lt Gaas

AbstractPseudodielectric functions of low temperature grown GaAs (LT GaAs) measured by spectroscopic ellipsometry are presented. The spectral range includes the El (2.92eV) and El+ΔAl (3.13eV) critical point structure of GaAs. A Lorentz-oscillator model was used to fit the dielectric function of LT GaAs for samples with nominal growth temperatures (Tg) varying from 200°C to 580°C. For Tg of 200°C, 30% and 19% broadenings and −0.01 leV and −0.007eV red shifts were found for the El and El+Δl structures respectively, compared with normal GaAs. The red shift can be explained in terms of a strain effect in the LT layer. In annealed LT GaAs the broadening decreased significantly and no red shift was found.

scholarly journals Laser-Combined Scanning Tunneling Microscopy on the Carrier Dynamics in Low-Temperature-Grown GaAs/AlGaAs/GaAs

2011 ◽  
Vol 2011 ◽  
pp. 1-9 ◽  
Author(s):  
Yasuhiko Terada ◽  
Shoji Yoshida ◽  
Osamu Takeuchi ◽  
Hidemi Shigekawa
Keyword(s):  
Low Temperature ◽  
Scanning Tunneling Microscopy ◽  
Temporal Resolution ◽  
Scanning Tunneling ◽  
High Temporal Resolution ◽  
Tunneling Microscopy ◽  
Recombination Lifetime ◽  
Recombination Lifetimes ◽  
Low Temperature Grown Gaas ◽  
Lt Gaas

We investigated carrier recombination dynamics in a low-temperature-grown GaAs (LT-GaAs)/AlGaAs/GaAs heterostructure by laser-combined scanning tunneling microscopy, shaken-pulse-pair-excited STM (SPPX-STM). With the AlGaAs interlayer as a barrier against the flow of photocarriers, recombination lifetimes in LT-GaAs of 4.0 ps and GaAs of 4.8 ns were successfully observed separately. We directly demonstrated the high temporal resolution of SPPX-STM by showing the recombination lifetime of carriers in LT-GaAs (4.0 ps) in the range of subpicosecond temporal resolution. In the carrier-lifetime-mapping measurement, a blurring of recombination lifetime up to 50 nm was observed at the LT-GaAs/AlGaAs boundary, which was discussed in consideration of the screening length of the electric field from the STM probe. The effect of the built-in potential on the signal, caused by the existence of LT-GaAs/AlGaAs/GaAs boundaries, was discussed in detail.

scholarly journals Femtosecond response time in beryllium-doped low-temperature-grown GaAs/AlAs multiple quantum wells

2001 ◽  
Vol 79 (6) ◽  
pp. 764-766 ◽  
Author(s):  
Tsuyoshi Okuno ◽  
Yasuaki Masumoto ◽  
Yasushi Sakuma ◽  
Yuuichi Hayasaki ◽  
Hiroshi Okamoto
Keyword(s):  
Low Temperature ◽  
Response Time ◽  
Quantum Wells ◽  
Multiple Quantum Wells ◽  
Multiple Quantum ◽  
Low Temperature Grown Gaas

Atomic Force Microscopy and EDX Analysis for Investigation Photoconductive LT-GaAs Terahertz Antennas

2018 ◽  
Vol 271 ◽  
pp. 92-97
Author(s):  
Sergey Nomoev ◽  
Ivan Vasilevskii ◽  
Erzhena Khartaeva
Keyword(s):  
Surface Roughness ◽  
Atomic Force Microscopy ◽  
Low Temperature ◽  
Atomic Force Microscope ◽  
Photoconductive Antenna ◽  
X Ray ◽  
Force Microscopy ◽  
Atomic Force ◽  
Low Temperature Grown Gaas ◽  
Lt Gaas

We investigate the influence of the surface properties of a low-temperature-grown GaAs photoconductive antenna on the terahertz (THz) response power. A comparison to the surface roughness which is extracted from an atomic force microscope is given. We used energy dispersive x-ray spectroscopy (EDX) measurements to determine the Ga/As compositional ratio in the LT-GaAs.

scholarly journals Электрические и тепловые свойства фотопроводящих антенн на основе In-=SUB=-x-=/SUB=-Ga-=SUB=-1-x-=/SUB=-As (x>0.3) с метаморфным буферным слоем для генерации терагерцового излучения

2017 ◽  
Vol 51 (9) ◽  
pp. 1267
Author(s):  
Д.С. Пономарев ◽  
Р.А. Хабибуллин ◽  
А.Э. Ячменев ◽  
А.Ю. Павлов ◽  
Д.Н. Слаповский ◽  
...  
Keyword(s):  
Low Temperature ◽  
Low Temperature Grown Gaas ◽  
Lt Gaas

Приведены результаты исследований электрических и тепловых свойств фотопроводящих антенн для генерации терагерцового излучения на основе выращенного в низкотемпературном режиме GaAs (low-temperature grown GaAs, LT-GaAs) и InxGa1-xAs c повышенным содержанием индия (x&gt;0.3). Показано, что мощность джоулева разогрева PH за счет влияния темнового тока в InxGa1-xAs в 3-5 раз превосходит аналогичную величину для LT-GaAs. Это обусловлено большой собственной проводимостью InxGa1-xAs при x&gt;0.38. Была разработана и изготовлена теплоотводящая оснастка для фотопроводящей антенны. Результаты численного моделирования показали, что использование теплоотвода позволяет уменьшить рабочую температуру антенны на 16&#37; для антенны на основе LT-GaAs на 40&#37; для антенны на основе In0.38Ga0.62As и на 64&#37; для антенны на основе In0.53Ga0.47As. DOI: 10.21883/FTP.2017.09.44893.8508

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