In-plane valence-band nonparabolicity and anisotropy in strained Si-Ge quantum wells

1993 ◽  
Vol 48 (20) ◽  
pp. 15112-15115 ◽  
Author(s):  
A. Zaslavsky ◽  
T. P. Smith ◽  
D. A. Grützmacher ◽  
S. Y. Lin ◽  
T. O. Sedgwick ◽  
...  
PIERS Online ◽  
2006 ◽  
Vol 2 (6) ◽  
pp. 562-566 ◽  
Author(s):  
Chun-Nan Chen ◽  
Kao-Feng Yarn ◽  
Win Jet Luo ◽  
Jih-Chen Chiang ◽  
Ikai Lo ◽  
...  

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.


1991 ◽  
Vol 240 ◽  
Author(s):  
Emil S. Koteies

ABSTRACTWe have developed a novel experimental technique for accurately determining band offsets in semiconductor quantum wells (QW). It is based on the fact that the ground state heavy- hole (HH) band energy is more sensitive to the depth of the valence band well than the light-hole (LH) band energy. Further, it is well known that as a function of the well width, Lz, the energy difference between the LH and HH excitons in a lattice matched, unstrained QW system experiences a maximum. Calculations show that the position, and more importantly, the magnitude of this maximum is a sensitive function of the valence band offset, Qy, which determines the depth of the valence band well. By fitting experimentally measured LH-HH splittings as a function of Lz, an accurate determination of band offsets can be derived. We further reduce the experimental uncertainty by plotting LH-HH as a function of HH energy (which is a function of Lz ) rather than Lz itself, since then all of the relevant parameters can be precisely determined from absorption spectroscopy alone. Using this technique, we have derived the conduction band offsets for several material systems and, where a consensus has developed, have obtained values in good agreement with other determinations.


1998 ◽  
Vol 533 ◽  
Author(s):  
Gregory Sun ◽  
Lionel Friedman ◽  
Richard A. Soref

AbstractWe have designed a parallel interminiband lasing in superlattice structures of coherently strained Si0.5Ge0.5/Si quantum wells (QWs). Population inversion is achieved between the non-parabolic heavy-hole valence minibands locally in-k-space. Lasing transition is at 5.4μm. Our analysis indicates that an optical gain of 134/cm can be obtained when the laser structure is pumped with a current density of 5kA/cm2.


1992 ◽  
Vol 46 (3) ◽  
pp. 1886-1888 ◽  
Author(s):  
Gérald Arnaud ◽  
Philippe Boring ◽  
Bernard Gil ◽  
Jean-Charles Garcia ◽  
Jean-Pierre Landesman ◽  
...  

2007 ◽  
Vol 1017 ◽  
Author(s):  
Seungwon Lee ◽  
Paul von Allmen

AbstractThe electronic structure for a strained silicon quantum well grown on a tilted SiGe substrate is calculated using an empirical tight-binding method. For a zero substrate tilt angle the two lowest minima of the conduction band define a non-zero valley splitting at the center of the Brillouin zone. A finite tilt angle for the substrate results in displacing the two lowest conduction band minima to finite k0 and -k0 in the Brillouin zone with equal energy. The vanishing of the valley splitting for quantum wells grown on tilted substrates is found to be a direct consequence of the periodicity of the steps at the interfaces between the quantum well and the buffer materials.


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