Growth mechanisms of GaN quantum dots and their optical properties

This paper describes the fabrication of quantum dots of GaN, a typical III-V nitride group semiconductor. On investigating GaN growth on the AlGaN mixed crystal surface to be used as a optical and electron confinement layer for device applications, it is found that two-dimensional step flow growth mode can be changed to three-dimensional growth mode by Si supply. This phenomenon is proposed to be effective for fabrication of GaN quantum dots. From the growth kinetics or the energy point of view, Si functions to prevent GaN step flow growth on the AlGaN surface. Furthermore, the free energy on the AlGaN surface is varied by additions of Si. The optical characteristics of GaN quantum dots are evaluated by the photoluminescence method. The dependence of the emission energy from GaN quantum dots on the dot size is confirmed. A laser structure was fabricated and stimulated emission was observed by optical pumping.