Pressure dependence of the valence-band discontinuity in GaAs/AlAs and GaAs/ Al x Ga 1…
1989; American Physical Society; Volume: 39; Issue: 8 Linguagem: Inglês
10.1103/physrevb.39.5546
ISSN1095-3795
AutoresJ.D. Lambkin, A.R. Adams, D. J. Dunstan, P. Dawson, C.T. Foxon,
Tópico(s)Optical properties and cooling technologies in crystalline materials
ResumoWe have performed high-pressure photoluminescence measurements on a type-II GaAs/AlAs superlattice at liquid-helium temperatures. The observed indirect transitions were found to have a pressure coefficient of -2.4\ifmmode\pm\else\textpm\fi{}0.1 meV/kbar, significantly larger in magnitude than the coefficient of -1.3 meV/kbar reported for the indirect gap of GaAs. This is interpreted as evidence for a pressure dependence of the valence-band discontinuity (\ensuremath{\Delta}${E}_{V}$) of approximately +1 meV/kbar. Our result is in excellent agreement with theoretical calculations of Van de Walle and Martin. Taken together with previously reported data, it suggests that the magnitude of d\ensuremath{\Delta}${E}_{V}$/dP is a linear function of the alloy composition of the barrier material. We show that the fractional conduction- and valence-band offsets of GaAs/${\mathrm{Al}}_{0.3}$${\mathrm{Ga}}_{0.7}$As are pressure dependent.
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