Fabrication and Characterization of In_xGa_1-xN Quantum Dots Using Nitridation of Nano-alloyed Droplet Growth Technique

We have studied the InGaN quantum dots (QDs) grown on a GaN pseudo template on a sapphire substrate (0001) using metal organic chemical vapor deposition (MOCVD). Self assembled InGaN QDs was successfully fabricated using nitridation of nano alloyed droplet (NNAD) method. The density, average diameter, and height of the InGaN QDs were estimated to be 1.0×10⁸ cm^-2, 50 nm, and 13 nm, respectively. The structural and optical properties of InGaN QDs were investigated using scanning electron microscopy (SEM), atomic force microscopy (AFM), and photoluminescence (PL). From the SEM image, it is clearly seen that In+Ga alloy droplets are uniformly distributed on GaN template. Further, InGaN QDs uniform distribution on the GaN/sapphire surface was observed by AFM. Broad emission from the QDs was observed around 580 nm which indicate the grown QDs have relatively high In composition due to low growth temperature. The broad and separated PL peak of QDs induced by the fluctuation in size and composition. Our result suggests that self-assembled InGaN QDs are fabricated well by using NNAD technique.