The emission spectrum of $p$-AlGaAs/GaAsP/$n$-AlGaAs diodes under uniaxial compression

New experimental data are presented on the effects of uniaxial compression of up to 4 kbar along the $[110]$ and $[1\bar10]$ crystallographic directions on the spectra of electroluminescence and the current-voltage characteristics of diodes based on $n$-Al$_x$Ga$_{1-x}$As/GaAs$_y$P$_{1-y}$/$p$-Al$_x$Ga$_{1-x}$As (${y=0.84}$) heterostructures that were designed for injection lasers. With increasing pressure, the spectra show a shift to shorter wavelengths, reaching 25 meV at 3 kbar; the intensity increases 2–3 times as well. Numerical calculations were carried out on the band structure of the investigated heterostructures under compression along the $[110]$ axis, which indicate the increase in the effective band gap in the quantum well (QW) GaAs$_y$P$_{1-y}$ , with a pressure coefficient of about 8.5 meV/kbar and reduction of the barrier height at the boundaries of the QW. The calculations predict the possibility that light and heavy holes crossover at pressures above 4.5–5 kbar. The increase in the effective band gap completely describes the experimental data on the shift of the electroluminescence spectra. The mixing of light and heavy holes when approaching the band crosspoint is the probable cause of an increase in the intensity of radiation under uniaxial compression.