Optical and structural studies of phase separation in InGaN film grown by MOCVD

We have studied the effects of growth temperature, film thickness, and Si d oping on the phase separation in InGaN films grown by metalorganic chemical vapor deposition. As the growth temperature decreased, the band-edge photo luminescence peak became splitted due to the In composition fluctuation in the InGaN film and finally separated into two discrete peaks corresponding to the epitaxial InGaN and InN-rich phase. The size and the In content of t he spinodally-formed InN-rich regions increased with increasing InGaN film thickness. The Si doping was found to suppress the composition fluctuation and the In incorporation in InGaN films.