Growth of In-rich InGaN Quantum Dots (QDs) by Metalorganic Chemical Vapor Deposition (MOCVD)

摘要

In-rich InGaN/GaN quantum dots (QDs) were successfully grown by metal-organic chemical vapor deposition. Growth at low temperatures below 700 C made it possible to obtain In-rich InGaN layer with In content over 70 % and was confirmed by electron probe microanalysis (EPMA) and x-ray diffraction (XRD). Uniform QDs were obtained with density of 1.3 x 1010 /sq cm with optimizing growth conditions. The density of QDs was further increased to 3.0 x 1010 /sq cm with AlGaN barrier layer. Strong photoluminescence (PL) emission from In-rich InGaN/GaN QDs was observed at room temperature and emission wavelength was varied from 404 nm to 454 nm depending on QD size. It was concluded that QDs showed higher radiative recombination efficiency from temperature dependent PL measurement.