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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, Weinheim)

The operation of InGaAs/GaAs/AlGaAs strained quantum-well lasers on 1.0° misoriented (111)B GaAs substrates is reported. The laser structures are grown by molecular beam epitaxy (MBE). Threshold current densities of 164 A/cm2 at 1072 nm were obtained for broad-area, uncoated devices with cavity lengths of 700 µ m.