High-Performance Green and Yellow LEDs Grown on ${\rm SiO}_{2}$ Nanorod Patterned GaN/Si Templates

High-performance GaN-based green and yellow light-emitting diodes (LEDs) are grown on SiO₂ nanorod patterned GaN/Si templates by metalorganic chemical vapor deposition. The high-density SiO₂ nanorods are prepared by nonlithographic HCl-treated indium tin oxide and dry etching. The dislocation density of GaN is significantly reduced by nanoscale epitaxial lateral overgrowth. In addition to the much improved green LED (505 and 530 nm) results, the fabricated yellow (565 nm) InGaN/GaN-based multiquantum well (MQW) LEDs on Si substrates are demonstrated for the first time. High-quality GaN buffer and localized states in MQWs are correlated to obtaining high-efficiency long-wavelength emission in our devices.