Electroreflectance and Photoluminescence Study on InGaN Alloys

Photoluminescence (PL) and electrore°ectance (ER)measurements on In-rich InxGa1¡xN .lms grown by using metal-organic chemical vapor deposition at 640 ±C and 670 ±C were performed. Franz-Keldysh Oscillations (FKO's) were observed in the ER spectra. The analysis of the FKO's shows phase separation of InN for the In0:8Ga0:2N .lm, regardless of the growth temperature, whereas in the PL spectrum multiple peaks were resolved only in the sample grown at 640 ±C. This indicates that phase separation exists in this kind of In-rich InGaN alloy independent of the growth temperature. From a deconvolution of the FKO signal in the ER spectra, the bandgap energy of In-rich InxGa1¡xN could be estimated. The dependence of the bandgap energy of the InxGa1¡xN alloy on the In composition (x) was obtained from this information. KCI Citation Count: 4