Luminescence and Raman measurements of In_yGa_1-yP (0.3<y<0.5) grown by gas-source molecular beam epitaxy

Abstract

We have measured the luminescence, luminescence excitation, and Raman spectra of undoped InyGa1-yP (0.3<y<0.5) films grown by gas-source molecular beam epitaxy on GaAs substrates. We observe strong excitonic luminescence over the entire composition range investigated. The band gap derived from the luminescence excitation spectra corresponds to that of a fully relaxed InGaP film with no residual strain, which is confirmed by the Raman measurements. The dependencies of the Raman modes on alloy composition and ordering effects are discussed.