Refractive indices measurement of (GaInP)<i>m</i>/(AlInP)<i>n</i> quasi-quaternaries and GaInP/AlInP multiple quantum wells

Abstract

Measurements of the refractive indices of (GaInP)m/(AlInP)n quasi-quaternaries (QQs), GaInP/AlInP multiple quantum wells (MQWs), and (AlxGa1−x)0.5In0.5P quaternaries were made systematically, using the reflectance method, in photon energy ranges nearly as high as up to the band gap. Data was fitted using the modified single effective oscillator (MSEO) method. A single oscillator energy (Eo) of 4.17+0.49xeq and dispersion energy (Ed) of 35.79–1.16xeq was obtained for (GaInP)m/(AlInP)2 QQs, where the equivalent Al composition xeq is defined by the stacking film thickness ratio xeq=d(AlInP)/[d(GaInP)+d(AlInP)]. Agreement of refractive indices obtained for QQs and quaternary compounds with equivalent xeq has been confirmed. Still, for the GaInP/AlInP MQWs, MSEO fitting was also agreeable, using the same oscillator energy Eo and dispersion energy Ed of the (GaInP)m/(AlInP)2 QQs with the same thickness ratio, and substituting band gap energy EΓ values shifted due to quantum effects.