Optical properties study of In_(.08)Ga_(.92)As/GaAs using spectral reflectance, photoreflectance and near-infrared Photoluminescence

摘要

Optical properties of In_(.08)Ga_(.92)As/GaAs structure grown by metal-organic vapor phase epitaxy have been investigated. Spectral reflectance (SR) and photoreflectance (PR) as well as near-infrared Photoluminescence (PL) were performed in this study. In fact, SR signals in the range 200-1700 nm provided specific parameters of materials such as optical constant spectra, sensitivity to wavelength and critical point energies. In addition, band gap energy was determined by both PR and optical absorption measurements at room temperature. Spin-orbit splitting, internal electric field and electro-optical energy were also calculated. Results provided by previous techniques present a good correlation and complementarities and agree well with the literature. On the other hand, the origins of 12 K PL peaks at 1.42,1.38 and 1.29 eV, have been identified by performing excitation power (P_(ex)) study. Finally, the peak at 1.38 eV has two regimes of variation with P_(ex) separated by a critical power around 50 mW.