Sheet Density and Well Thickness Effects on Photoluminescence from Pseudomorphic HEMT Structures

1988 ◽  
Vol 144 ◽  
Author(s):  
C. Colvard ◽  
N. Nouri ◽  
H. Lee ◽  
D. Ackley
Keyword(s):  
Low Temperature ◽  
Quantum Well ◽  
Fermi Level ◽  
Excellent Agreement ◽  
Fermi Energy ◽  
Carrier Density ◽  
Two Dimensional ◽  
Fermi Edge ◽  
Low Temperature Photoluminescence ◽  
Sheet Density

ABSTRACTLow temperature photoluminescence was studied in a large number of pseudomorphic HEMT's having an InxGa1−xAs quantum well. The spectra show strong qualitative differences when the Fermi level is above or below the second conduction subband, and in the latter case they are power dependent. A slight enhancement is seen at the Fermi edge only when it lies close to the higher subband. Excellent agreement is found between the measured Fermi energy and the two-dimensional carrier density in the well.

Low-temperature Photoluminescence Characteristics of GaAs Quantum-well Waveguides

2011 ◽  
Author(s):  
Y. Nagao ◽  
Y. Kuwamura ◽  
A. Nizamuddin ◽  
T. Nakahora ◽  
T. Hotani ◽  
...  
Keyword(s):  
Low Temperature ◽  
Quantum Well ◽  
Low Temperature Photoluminescence

scholarly journals Спектр излучения и стабильность двух типов электронно-дырочной жидкости в мелких Si/Si-=SUB=-1-x-=/SUB=-Ge-=SUB=-x-=/SUB=-Si квантовых ямах

2020 ◽  
Vol 62 (4) ◽  
pp. 529
Author(s):  
А.А. Васильченко ◽  
В.С. Кривобок ◽  
С.Н. Николаев ◽  
В.С. Багаев ◽  
Е.Е. Онищенко ◽  
...  
Keyword(s):  
Low Temperature ◽  
Quantum Wells ◽  
Density Functional ◽  
Two Dimensional ◽  
Photoluminescence Spectra ◽  
Dimensional Electron ◽  
Electron Hole ◽  
Germanium Content ◽  
Well Design ◽  
Low Temperature Photoluminescence

Abstract Based on calculations within the density functional theory and an analysis of low-temperature photoluminescence spectra, the structure of electron–hole liquid in shallow Si/Si_1 – _ x Ge_ x Si (100) quantum wells 5 nm wide with germanium content x = 3–5.5% is studied. It is shown that the energy of quasi-two-dimensional electron–hole liquid localized in quantum wells for this composition range as a function of carrier concentration exhibits two local minima. The position of the deeper (major) minimum depends on the quantum well design and controls properties of quasi-two-dimensional electron–hole liquid at low temperatures. For the series of Si/Si_1 – _ x Ge_ x Si quantum wells, modification of properties of electron–hole liquid was experimentally shown, which can be interpreted as a change of the major minimum due to an increases in the germanium concentration in the Si_1 – _ x Ge_ x layer. The effect of the multicomponent composition (electrons, light and heavy holes) of the electron–hole liquid on low-temperature photoluminescence spectra of Si/Si_1 ‒ _ x Ge_ x Si quantum wells is discussed.

Evaluation of p-Type Doping for (1,1,-2,0) Epitaxial Layers Grown on α-Cut (1,1,-2,0) 4H-SiC Substrates

2005 ◽  
Vol 483-485 ◽  
pp. 117-120 ◽  
Author(s):  
Caroline Blanc ◽  
Marcin Zielinski ◽  
Véronique Soulière ◽  
C. Sartel ◽  
Sandrine Juillaguet ◽  
...  
Keyword(s):  
Experimental Investigation ◽  
Low Temperature ◽  
Hall Effect ◽  
Excellent Agreement ◽  
Doping Level ◽  
Epitaxial Layers ◽  
Residual N ◽  
P Type ◽  
Low Temperature Photoluminescence

We report an experimental investigation of the residual (n-type) and intentional (p-type) doping level of <11-20> epitaxial layers grown on a-cut 4H-SiC substrates. Using SIMS, C(V) measurements, low temperature photoluminescence and Hall effect investigations, we show that nitrogen incorporates 3 times more than usually found for <0001> surfaces. Conversely, aluminum incorporates 8 times less. Altogether, this is in excellent agreement with previous results from stepcontrolled epitaxy.

Electronic Structure of δ-Pu and PuCoGa5 from Photoemission and the Mixed Level Model

2003 ◽  
Vol 802 ◽  
Author(s):  
John J. Joyce ◽  
John M. Wills ◽  
Tomasz Durakiewicz ◽  
Elzbieta Guziewicz ◽  
Martin T. Butterfield ◽  
...  
Keyword(s):  
Electronic Structure ◽  
Fermi Level ◽  
Electronic Properties ◽  
Excellent Agreement ◽  
Fermi Energy ◽  
Photoelectron Spectroscopy ◽  
Spectral Intensity ◽  
Δ Phase ◽  
Level Model ◽  
Photoemission Data

ABSTRACTThe electronic structure of δ-phase Pu metal and the Pu-based superconductor PuCoGa5 is explored using photoelectron spectroscopy and a novel theoretical scheme. Excellent agreement between calculation and experiment defines a path forward for understanding electronic structure aspects of Pu-based materials. The photoemission results show two separate regions of 5f electron spectral intensity, one at the Fermi energy and another centered 1.2 eV below the Fermi level. A comparison is made between the photoemission data and five computational schemes for δ-Pu. The results for δ-Pu and PuCoGa5 indicate 5f electron behavior on the threshold between localized and itinerant and a broader framework for understanding the fundamental electronic properties of the Pu 5f levels in general within two configurations, one localized and one itinerant.

Irradiation-Induced Damage and Intermixing of GaAs-Algaas Quantum Wells

1995 ◽  
Vol 396 ◽  
Author(s):  
H.H. Tan ◽  
J.S. Williams ◽  
C. Jagadish ◽  
P.T. Burke ◽  
M. Gal
Keyword(s):  
Low Temperature ◽  
Quantum Well ◽  
Quantum Wells ◽  
Ion Irradiation ◽  
Large Energy ◽  
Good Recovery ◽  
Quantum Well Structures ◽  
Delicate Balance ◽  
Higher Doses ◽  
Low Temperature Photoluminescence

AbstractA comparison of ion irradiation-induced intermixing in GaAs-Al0.54Gao46As quantum well structures with H, O and As ions is investigated by low temperature photoluminescence. Very large energy shifts are observed together with good recovery of the photoluminescence intensities after annealing in samples irradiated with protons. No saturation in the energy shifts is observed in samples irradiated even up to a dose of 4.3 x 1016 cm-2. Similar large shifts with low absorption are also observed in O and As implanted samples but at a significantly lower ion dose. However, both the heavier ions show a saturation effect in the degree of intermixng at higher doses. The degree of intermixing is believed to be a delicate balance among multiple competing processes that occurs across the interface.

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