Growth and characterization of InGaN nanodots hybrid with InGaN/GaN quantum wells

Uniform InGaN nanodots were successfully grown on SiO2 pretreated GaN surface. It was found that the InGaN nanodots were 20 nm in diameter and 5 nm in height, approximately. After the growth of two peri- ods of InGaN/GaN quantum wells on the surface of In- GaN nanodots, nanodot structure still formed in the In- GaN well layer caused by the enhanced phase separation phenomenon. Dual-color emissions with different behavior were observed from photoluminescence (PL) spectrum of InGaN nanodots hybrid with InGaN/GaN quantum wells. A significant blueshift and a linewidth broadening were mea- sured for the low-energy peak as the increase of PL excita- tion power, while a slight blueshift and a linewidth narrow- ing occurred for the high-energy peak. Accordingly, these two peaks were assigned to be from the In-rich nanodots and quantized state transition from the InGaN/GaN quan- tum wells with indium content, respectively.