Optical microcavity based on a single ZnO microwire grown on Si(111) substrate by catalyst-free mist chemical vapor deposition

ZnO nano- and microwires were grown on Si(111) substrates by mist chemical vapor deposition (mist-CVD). In 30 min of crystal growth, ZnO nanowires of approximately 100–500 nm diameters and 800–1000 nm length were grown. In 4 h of crystal growth, ZnO microwires were grown with some of them having a diameter and length of more than 2 and 9 µm, respectively. ZnO crystals grown for 30 min and for 4 h exhibited clear room-temperature photoluminescence (RT-PL) peaks near the band gap energy. Under high-optically pumped conditions, some ZnO microwires exhibited sharp peaks in RT-PL spectra, indicating that optically pumped lasing actions were obtained based on optical microcavities formed in a ZnO microwire.