Intersubband and interband optical absorption study of strain-compensated InGaAs-InGaP superlattices grown on GaAs

Abstract

Strain-compensated In/sub 0.32/Ga/sub 0.68/As-In/sub 0.32/Ga/sub 0.68/P superlattices have been grown on semiinsulating [001] GaAs substrates using gas-source molecular-beam epitaxy and their subband structures investigated. Both visible and mid-infrared optical transmission measurements were used to determine the energies of the 1e-2e transitions as a function of superlattice structure. The highest energy 1e-2e transition obtained is 218 meV, corresponding to a wavelength of 5.7 /spl mu/m. The conduction band offset between the strained In/sub 0.32/Ga/sub 0.68/As and In/sub 0.32/Ga/sub 0.68/P appears to lie between 400 and 500 meV.