Strong room-temperature near-ultraviolet emission from In-rich InGaN/GaN nanostructures grown by metalorganic chemical vapor deposition

Abstract

We report the successful growth of In-rich InGaN/GaN nanostructures such as multiple quantum wells (MQWs) and quantum dots (QDs) by metalorganic chemical vapor deposition (MOCVD). Introduction of a relatively high growth temperature (730°C) made it possible to grow In-rich InGaN/GaN QWs, and growth interruption (GI) was effectively used to improve the structural and optical properties of the QWs. To enhance thermal characteristics, an artificial formation of In-rich InGaN/GaN QDs was made at a relatively lower growth temperature (650°C) than that of QWs. The well width of the In-rich InGaN/GaN QWs and the dot height of the In-rich InGaN/GaN QDs were both approximately 1 nm, and we obtained strong room-temperature near-ultraviolet (UV) emission from these In-rich InGaN/GaN nanostructures. This strongly suggests that ultrathin In-rich InGaN nanostructures can be a new candidate for a near-UV source, which might replace the conventional low-indium-content (<10%), thicker InGaN QW.