Effects of intervalence band coherences on the coherently coupled heavy-hole–light-hole Stark shift in semiconductor quantum wells

2002 ◽  
Vol 65 (24) ◽  
Author(s):  
I. Rumyantsev ◽  
N. H. Kwong ◽  
R. Takayama ◽  
R. Binder
2019 ◽  
Vol 2019 ◽  
pp. 1-7
Author(s):  
Takuya Kawazu

Optical properties of GaAs/AlGaAs quantum wells (QWs) in the vicinity of InAlAs quantum dots (QDs) were studied and compared with a theoretical model to clarify how the QD strain affects the electronic states in the nearby QW. In0.4Al0.6As QDs are embedded at the top of the QWs; the QD layer acts as a source of strain as well as an energy barrier. Photoluminescence excitation (PLE) measurements showed that the QD formation leads to the increase in the ratio Ie-lh/Ie-hh of the PLE intensities for the light hole (lh) and the heavy hole (hh), indicating the presence of the valence band mixing. We also theoretically calculated the hh-lh mixing in the QW due to the nearby QD strain and evaluated the PLE ratio Ie-lh/Ie-hh.


2007 ◽  
Vol 17 (01) ◽  
pp. 115-120
Author(s):  
N. Sustersic ◽  
S. Kim ◽  
P.-C. Lv ◽  
M. Coppinger ◽  
T. Troeger ◽  
...  

In this paper, we report on current pumped THz emitting devices based on intersubband transitions in SiGe quantum wells. The spectral lines occurred in a range from 5 to 12 THz depending on the quantum well width, Ge concentration in the well, and device temperature. A time-averaged power of 15 nW was extracted from a 16 period SiGe/Si superlattice with quantum wells 22 Å thick, at a device temperature of 30 K and a drive current of 550 mA. A net quantum efficiency of approximately 3 × 10-4 was calculated from the power and drive current, 30 times higher than reported for comparable quantum cascades utilizing heavy-hole to heavy-hole transitions and, taking into account the number of quantum well periods, approximately four times larger than for electroluminescence reported previously from a device utilizing light-hole to heavy-hole transitions.


1985 ◽  
Vol 56 ◽  
Author(s):  
H. NEFF ◽  
K. J. BACHMANN ◽  
W. D. LAIDIG

AbstractEmploying temperature dependent photoconductivity, photoluminescence and photoreflectivity measurements, we have analyzed a GaAs-AlAs multiple quantum well. The above optical techniques clearly resolve the fundamental inter-subband transitions, including heavy hole-light hole splittings. At T < 60K an anomalously high photoconductivity was discovered below the direct inter-subband transitions and is attributed tentatively to the presence of extrinsic interface states within the bandgap. For T > l00K the fundamental indirect transition was discovered and associated with LO (L) - phonon absorption.


1987 ◽  
Vol 36 (12) ◽  
pp. 6581-6584 ◽  
Author(s):  
H. Mathieu ◽  
P. Lefebvre ◽  
J. Allegre ◽  
B. Gil ◽  
A. Regreny

1999 ◽  
Vol 60 (11) ◽  
pp. 8267-8275 ◽  
Author(s):  
Arthur L. Smirl ◽  
Martin J. Stevens ◽  
X. Chen ◽  
O. Buccafusca

1993 ◽  
Vol 47 (11) ◽  
pp. 6758-6761 ◽  
Author(s):  
T. S. Moise ◽  
L. J. Guido ◽  
R. C. Barker

1987 ◽  
Vol 91 ◽  
Author(s):  
C. Jagannath ◽  
S. Zemon ◽  
P. Norris ◽  
B.S. Elman ◽  
S.K. Shastry

ABSTRACTPhotoluminescence and photoluminescence excitation spectroscopies are utilized to study excitons in GaAs/AlGaAs quantum wells (QW's) fabricated using MBE on MOCVD grown GaAs/Si. The experimental results are understood in terms of the biaxial tension of approximately 3 kbar present in the plane of growth for both the QW's and the GaAs buffer. An important consequence of the biaxial tension is that for QW's with well widths larger than ≈15 nm the light- and heavy- hole sub-bands cross each other in energy. This results in the light-hole exciton energy being lower than that of the heavy-hole exciton, opposite to the case of QW's grown on GaAs substrates.


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