ABSTRACT
Ultrathin GaAs needle-shaped microcrystals (whiskers) as thin as 20 nm and 2 to 3 (μm long are grown by organometallic vapor phase epitaxy. The whiskers are selectively grown within a SiO2 patterned substrate surface, and the growth axis is parallel to the [111] direction. From transmission electron microscopic analysis, the crystal structure coincides with that of zincblende at a growth temperature of 460 °C, but changes to that of wurtzite above 500 °C. A p–n junction along the wire is grown by changing dopants from silicon to carbon during growth. Light emission from the p–n junction is observed at a wavelength of 920 nm in continuous operation at room temperature.
