Strain-induced valence-subband splitting in III-V semiconductors

Abstract

A (001) axial strain introduces an additional term, known as the C4 matrix element, into the valence-band Hamiltonian of III-V semiconductors, proportional to the axial strain and to k~, the wavevector component perpendicular to the strain axis. This matrix element has been ignored in all previous valence-subband calculations. We use the empirical pseudopotential method and the tight-binding method to calculate the magnitude of C4 in the III-V and selected II-VI semiconductors. The calculated values are smaller than but comparable to the experimentally determined value in InSb. We then present envelope-function calculations which show how the C4 term may particularly acct the valencesubband structure of quantum wells under biaxial tension (e.g. , Ga-rich In"Gal "As on InP), splitting the degeneracy of the highest valence subband, and shifting the valence-band maximum from the Brillouin-zone center. The strain-induced band splittings are an order of magnitude larger than those in unstrained bulk material and may be measurable in wells with moderate strain (lattice mismatch =1%).Finally, we discuss the inhuence of the C4 term on optical, transport, and cyclotron-resonance data.

Energy spectrum and topology evolution of the Fermi surface of two-dimensional holes inGaAs/Al0.5Ga0.5Kolokolov1, Savin2, Beneslavski3 et al. 1999Phys. Rev. B4710330View full textAdd to dashboardCite

“…In p-type In x Ga 1Ϫx As/In x Ga 1Ϫx As y P 1Ϫy high biaxial strain leads to large shifts of the hole subbands, 6 the light-hole subband becoming the upper one at a definite biaxial tension. The biaxial strain affects the value of the splitting in the system, 6,7 and compressive and tensile strains can strongly increase or suppress existing splitting. 6 The influence of uniaxial stress on the valence-band structure was also studied, but only for the case of square wells.…”

Scattering theory of charge-current–induced magnetization dynamics

“…[13], where b = −1.7 eV [13], ax ≡ ( zz − xx ) = −0.005 [12,13], n,n are diagonal elements of the stress tensor, C 4 = 5 eVÅ [13],and δ mn is the Kronecker delta. The GaAs leads are model by H L , only.…”

Nanometer‐scale cathodoluminescence analysis of GaAs and its application to the assessment of laser diode

“…13). Accordingly, GaAs luminescence transitions, including the variation of luminescence band line shape ( i.e ., due to a variety of effects, such as temperature, stress, doping type, doping level) are well documented in the literature 13–20. The spectroscopic features involved with the luminescence spectrum of GaAs have been paid considerable attention in search for the physical implications of highly graded strain fields on luminescence emission.…”