Electroreflectance and photoluminescence study on InGaN alloys

초록

Photoluminescence (PL) and electroreflectance (ER) measurements on In-rich InxGa1-xN films grown by using metal-organic chemical vapor deposition at 640 degrees C and 670 degrees 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 film, regardless of the growth temperature, whereas in the PL spectrum multiple peaks were resolved only in the sample grown at 640 degrees 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.

키워드