Selective growth of InGaN quantum dot structures and their microphotoluminescence at room temperature

We have fabricated InGaN quantum dot (QD) structures on hexagonal pyramids of GaN, using metalorganic chemical vapor deposition with selective growth. Intense photoluminescence was observed from the sample at room temperature. To directly observe the emitting areas, microphotoluminescence intensity images with a spatial resolution of a few hundred nanometers were used. The images show the emission was only from the tops of the hexagonal pyramids. The width of the emitting areas is about 300 nm, which is comparable to the spatial resolution of the images. Such a narrow width of emission areas indicates that InGaN QDs are formed on the tops of pyramids.