Hexagonal ZnO microdisk grown by mist chemical vapor deposition on c-plane sapphire substrate and lasing actions

Abstract Hexagonal ZnO microdisks were grown by mist CVD for 6 h. The microdisks when viewed from the top were typically hexagonal with diameters of a few micrometers, and their typical three-dimensional shape was a hexagonal pyramid. Sharp peaks appeared in the RT photoluminescence (PL) spectra observed from a single hexagonal ZnO microdisk under high optically pumped conditions, and they are assumed to correspond to lasing actions. We also examined the temperature dependence of these sharp peaks in the PL spectra.