Indirect barrier electron-hole gas transitions in mixed type-I–type-II GaAs/AlAs multiple quantum wells

2001 ◽  
Vol 64 (3) ◽  
Author(s):  
R. Guliamov ◽  
E. Lifshitz ◽  
E. Cohen ◽  
Arza Ron ◽  
L. N. Pfeiffer
Keyword(s):  
Quantum Wells ◽  
Mixed Type ◽  
Multiple Quantum Wells ◽  
Multiple Quantum ◽  
Type I ◽  
Type Ii ◽  
Electron Hole

Optical nonlinearities in mixed type I–type II GaAs/AlAs multiple quantum wells

1992 ◽  
Vol 45 (23) ◽  
pp. 13499-13508 ◽  
Author(s):  
I. Galbraith ◽  
P. Dawson ◽  
C. T. Foxon
Keyword(s):  
Quantum Wells ◽  
Mixed Type ◽  
Multiple Quantum Wells ◽  
Multiple Quantum ◽  
Type I ◽  
Optical Nonlinearities ◽  
Type Ii

Magnetic-field induced type I-type II transition in multiple quantum wells

1996 ◽  
Vol 159 (1-4) ◽  
pp. 967-971 ◽  
Author(s):  
Shinji Kuroda ◽  
Kazutoshi Kojima ◽  
Kôki Takita ◽  
Kazuhito Uchida ◽  
Noboru Miura
Keyword(s):  
Magnetic Field ◽  
Quantum Wells ◽  
Multiple Quantum Wells ◽  
Multiple Quantum ◽  
Type I ◽  
Type Ii

Optical characterization of type-II ZnO/ZnS multiple quantum wells grown by atomic layer deposition

2020 ◽  
Vol 694 ◽  
pp. 137740 ◽  
Author(s):  
Mostafa Afifi Hassan ◽  
Aadil Waseem ◽  
Muhammad Ali Johar ◽  
Sou Young Yu ◽  
June Key Lee ◽  
...  
Keyword(s):  
Atomic Layer Deposition ◽  
Quantum Wells ◽  
Atomic Layer ◽  
Optical Characterization ◽  
Multiple Quantum Wells ◽  
Multiple Quantum ◽  
Type Ii ◽  
Layer Deposition

Photoluminescence Studies of [(CdSe)1(ZnSe)2]9-ZnSeTe Multiple Quantum Wells Under High Pressure

1994 ◽  
Vol 358 ◽  
Author(s):  
Z.P. Wang ◽  
Z.X. Liu ◽  
H.X. Han ◽  
J.Q. Zhang ◽  
G.H. Li ◽  
...  
Keyword(s):  
High Pressure ◽  
Quantum Wells ◽  
Liquid Nitrogen Temperature ◽  
Multiple Quantum Wells ◽  
Multiple Quantum ◽  
Type I ◽  
Short Period ◽  
Heavy Hole Subband ◽  
Photoluminescence Studies ◽  
Increasing Temperature

ABSTRACTWe have performed photoluminescence (PL) measurements at liquid nitrogen temperature under high pressure up to 5.5 GPa and in the temperature range 10-300 K at atmospheric pressure on {(ZnSe)30(ZnSe0.92Te0.08)30(ZnSe)30[(CdSe)1(ZnSe)2]9}x5 multiple quantum wells. The PL peaks, EB, E1 and Ew corresponding to the band edge luminescence in ZnSe barrier layer, the transitions from the first conduction subband to the heavy-hole subband in ZnSe0.92Te0.08 layers and [(CdSe)1(ZnSe)2]9 ultra short period superlattice quantum well (SPSLQW) layers have been observed. Experimental results show that ZnSe0.92Te0.08/ZnSe forms a type-I superlattice (SL) in contrast to the type-II ZnSe/ZnTe SL. The pressure coefficients of the EB, E1 and Ew exciton peaks have been determined as 67, 63 and 56 meV/GPa, respectively. With increasing temperature (or pressure), the E1 peak-intensity drastically decreases which is attributed to the thermal effect (or the appearance of many defects in ZnSe0.92Te0.08 under higher pressure).

TEMPERATURE DEPENDENCE OF PHOTOLUMINESCENCE OF FLAT AND UNDULATED SiGe/Si MULTIPLE QUANTUM WELLS

2002 ◽  
Vol 16 (28n29) ◽  
pp. 4211-4214 ◽  
Author(s):  
B. W. CHENG ◽  
J. G. ZHANG ◽  
Y. H. ZUO ◽  
R. W. MAO ◽  
C. J. HUANG ◽  
...  
Keyword(s):  
Elevated Temperature ◽  
Quantum Wells ◽  
Blue Shift ◽  
Band Alignment ◽  
Multiple Quantum Wells ◽  
Luminescence Spectra ◽  
Multiple Quantum ◽  
Type Ii ◽  
Thermally Activated ◽  
Strained Sige

Photoluminescence (PL) of strained SiGe/Si multiple quantum wells (MQW) with flat and undulated SiGe well layers was studied at different temperature. With elevated temperature from 10K, the no-phonon (NP) peak of the SiGe layers in the flat samples has firstly a blue shift due to the dominant transition converting from bound excitons (BE) to free excitons (FE), and then has a red shift when the temperature is higher than 30K because of the narrowing of the band gap. In the undulated sample, however, monotonous blue shift was observed as the temperature was elevated from 10 K to 287 K. The thermally activated electrons, confined in Si due to type-II band alignment, leak into the SiGe crest regions, and the leakage is enhanced with the elevated temperature. It results in a blue shift of the SiGe luminescence spectra.

Study of Near-Threshold Gain Mechanisms in MOCVD-Grown GaN Epilayers and InGaN/GaN Heterostructures

1999 ◽  
Vol 572 ◽  
Author(s):  
S. Bidnyk ◽  
T. J. Schmidt ◽  
B. D. Little ◽  
J. J. Song
Keyword(s):  
Quantum Wells ◽  
Stimulated Emission ◽  
Multiple Quantum Wells ◽  
Multiple Quantum ◽  
Optically Pumped ◽  
Electron Hole ◽  
Electron Hole Plasma ◽  
Narrow Emission ◽  
Threshold Gain ◽  
Near Threshold

ABSTRACTWe report the results of an experimental study on near-threshold gain mechanisms in optically pumped GaN epilayers and InGaN/GaN heterostructures at temperatures as high as 700 K. We show that the dominant near-threshold gain mechanism in GaN epilayers is inelastic excitonexciton scattering for temperatures below ∼ 150 K, characterized by band-filling phenomena and a relatively low stimulated emission (SE) threshold. An analysis of both the temperature dependence of the SE threshold and the relative shift between stimulated and band-edge related emission indicates electron-hole plasma is the dominant gain mechanism for temperatures exceeding 150 K. The dominant mechanism for SE in InGaN epilayers and InGaN/GaN multiple quantum wells was found to be the recombination of carriers localized at potential fluctuations resulting from nonuniform indium incorporation. The SE spectra from InGaN epilayers and multiple quantum wells were comprised of extremely narrow emission lines and no spectral broadening of the lines was observed as the temperature was raised from 10 K to over 550 K. Based on the presented results, we suggest a method for significantly reducing the carrier densities needed to achieve population inversion in GaN, allowing for the development of GaNactive-medium laser diodes.

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