Room-Temperature Pulsed Operation of GaN-Based Laser Diodes on a-Face Sapphire Substrate Grown by Low-Pressure Metalorganic Chemical Vapor Deposition

We report on the room-temperature pulsed current operation of GaN-based laser diodes on a (1120) (a-face) sapphire substrate grown by low-pressure metalorganic chemical vapor deposition (LP MOCVD). Ethyl biscyclopentadienyl magnesium (Et-Cp2Mg) and methyl silane (Me-SiH3) were used as precursors for dopants. The cavity mirror facets were formed by cleaving an a-face sapphire substrate along (1102) (r-face). The threshold current density was 41 kA/cm2 and the operating voltage at the threshold was 35 V. Above the threshold, laser emission was observed at 411 nm.