Growth and characterization of GaN grown on moth-eye patterned sapphire substrates

Abstract

To realize high-efficiency light-emitting diodes (LEDs), it is necessary to increase light extraction efficiency. Therefore, the introduction of a moth-eye structure, which consists of periodic cones with a pitch of optical wavelength magnitude, into a sapphire surface before the epitaxial growth of nitride films is very promising for reducing the reflectivity of light resulting in high light extraction efficiency. 450 nm GaInN/GaN LEDs were fabricated on conventional and moth-eye substrates by metal organic vapor phase epitaxy (MOVPE). The intensety of room-temperature photoluminescence emitted from the LED with the moth-eye-patterned sapphire substrate was 1.6 times higher than that emitted from the LED without the moth-eye substrate. Under a current injection of 50 mA, the output power of the moth-eye LED is 3.6 times higher than that of the conventional LED. © 2010 Wiley-VCH Verlag GmbH & Co. KGaA.