Static and modulated reflectance measurements on III--V compounds and alloys.

Abstract

Static and modulated reflectance measurements were made on samples of some III-V compounds and their alloys. Multiplet structures resolved in the reflectance spectra of III-V compounds in the energy range 3.5--7.5 eV led to the determination of the spin orbit splittings Delta0', Delta 2, Delta1', DL3V and ▵L3C . Structure was observed in the thermoreflectance spectra of III-V compounds in the energy range 1.5--6.0 eV and it was assigned to interband transitions. Results enabled comparison with previous data obtained using other techniques. Static and modulated reflectance measurements confirmed the nonlinear variation of energy gaps with composition in GaxIn 1-xSb alloy. Similar data was obtained for InAs1-xP x and InSb1-xAsx alloys from electroreflectance measurements. Results on five III-V alloys were analysed, fitting a quadratic equation to the energy gap variation with composition curves. The total bowing parameters determined experimentally were compared with theoretical values. The spin orbit splitting Delta1 was also found to vary nonlinearly with composition in the five alloy systems investigated and the bowing parameters were related to the atomic spin orbit splittings of the alloying elements.