Optical properties of highly disordered InGaP by solid-source molecular beam epitaxy with a GaP decomposition source

Abstract

Photoluminescence (PL) spectra and Raman spectra have been utilized to study the optical properties of epitaxial InGaP grown on (0 0 1) GaAs substrate by solid-source molecular beam epitaxy with a GaP decomposition source .The 15 K PL spectrum of 3 μm-thick InGaP epilayer grown under optimized conditions ( T s=460°C, V/III=15) shows that the PL peak energy is as high as 1.998 ev and the PL full-width at half-maximum is 5.26 meV, which is the narrowest value reported. The temperature dependence of PL spectrum exhibits normal behavior. The Raman scattering spectrum at room temperature shows the ratio b/ a, where b and a represent the valley depth between the GaP- and InP-like LO peak and the InP-like LO peak height, respectively, is as high as 0.45, which is near the largest value ever reported. All these results demonstrate that the InGaP grown under optimized conditions ( T s=460°C, V/III=15) by solid-source molecular beam epitaxy with a GaP decomposition source is highly disordered.