InGaN quantum wells and dots on initially shaped GaN islands: Growth and luminescence studies
Wang, G. B.
Fang, Z. L.
- 物理技术－已发表论文 
Direct growth of InGaN active layers on initially shaped pyramid-like GaN islands of low dislocation density, realized by enhanced island growth via slightly Si doping in the GaN islands, was investigated in detail. Scanning transmission electron microscopy (STEM) studies reveal the selective growth of relatively thin quantum wells (QWs) on semipolar sidewall facets, whereas In-rich InGaN quantum dots (QDs) form on the island apex. Spatially resolved scanning electron microscopy (SEM) and cathodoluminescence (CL) studies show strong emission from the island sites, whereas very weak emission arises from the nonisland sites, suggesting the preferential growth of InGaN active layers on the GaN islands rather than on the SiNx-treated nonisland sites. Polychromatic emissions from the InGaN QWs on island sidewall and top facets, and the In-rich InGaN QDs on the island apex were observed. Studies on the growth mechanism and properties of InGaN/GaN QWs on nanoscale faceted islands may serve as a nanoscale investigating tool for further studies of GaN island shaping and shape variations during heteroepitaxy in the early growth stages.
CitationPHYSICA STATUS SOLIDI A-APPLICATIONS AND MATERIALS SCIENCE，2012,209（8）：1445-1450