Deformation potentials of the direct and indirect absorption edges of GaP

作者：Henry Mathieu, P. Merle, E.L. Ameziane, B. Archilla, Jean Camassel, G. Poiblaud · 发表于：Physical review. B, Condensed matter · 年份：1979 · DOI：10.1103/physrevb.19.2209 · 被引用次数：90 · 研究领域：Semiconductor Quantum Structures and Devices、Acoustic Wave Resonator Technologies、Solid-state spectroscopy and crystallography

We present uniaxial-stress experiments performed on the direct and indirect exciton spectrum of GaP. Two direct transitions (${E}_{0}$ and ${E}_{0}+{\ensuremath{\Delta}}_{0}$) and three indirect phonon-assisted transitions (LA, TA, and TO phonon modes) have been investigated at 77 and 4.2\ifmmode^\circ\else\textdegree\fi{}K, respectively. Very-high-stress conditions have been achieved in this work ($X=19$kbar) which correspond to an axial deformation $\frac{\ensuremath{\delta}l}{l}=2\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}2}$, reaching the elastic limit of the material. We have been able to determine all linear and nonlinear deformation potentials that describe the stress dependence of the topmost valence bands (${\ensuremath{\Gamma}}_{7}$ and ${\ensuremath{\Gamma}}_{8}$) and of the lowest minima of the conduction band (${\ensuremath{\Gamma}}_{6}$ and ${X}_{6}$). The stress splitting of the valence band is produced by (i) the orbital-strain interaction, which is described by two deformation potentials ${b}_{1}$ and ${d}_{1}$, and (ii) the stress-dependent spin-orbit interaction which is described by two extra parameters ${b}_{2}$ and ${d}_{2}$. We find $b={b}_{1}+2$ ${b}_{2}=\ensuremath{-}(1.5\ifmmode\pm\else\textpm\fi{}0.2)$ eV, ${b}_{2}=+(0.2\ifmmode\pm\else\textpm\fi{}0.2)$ eV, $d={d}_{1}+2$ ${d}_{2}=\ensuremath{-}(4.6\ifmmode\pm\else\textpm\fi{}0.2)$ eV, and ${d}_{2}=+(0.3\ifmmode\pm\else\textpm\fi{}0.2)$ eV. The effect of hydrostatic deformation is again in...