Polarized photoluminescence measurements of the valence-band splitting in single-variant, spontaneously orderedGaInP2

In this paper, polarized photoluminescence is used to study the Γ-point valence-band structure of single-variant, spontaneously ordered ${\mathrm{GaInP}}_2$. A laser beam is focused onto the {110} cleaved edges of the epilayer, and the resultant photoluminescence is analyzed in the backscattering geometry. This ‘‘edge-on’’ arrangement allows us to access directly the polarization selection rules both parallel and perpendicular to the ordering axis, and it shows that the axis is [11¯1], in agreement with transmission-electron-diffraction measurements. This spectroscopic technique does not require the use of deconvolution methods to resolve the crystal-field transition from the conduction band to the crystal-field valence band, and as such provides a direct measurement of the CuPt selection rules and valence-band splitting in ${\mathrm{GaInP}}_2$.