High-performance UV emitter grown on high-crystalline-quality AlGaN underlying layer

✍ Scribed by Tsuzuki, Hirotoshi (author);Mori, Fumiaki (author);Takeda, Kenichiro (author);Ichikawa, Tomoki (author);Iwaya, Motoaki (author);Kamiyama, Satoshi (author);Amano, Hiroshi (author);Akasaki, Isamu (author);Yoshida, Harumasa (author);Kuwabara, Masakazu (author);Yamashita, Yoji (author);Kan, Hirofumi (author)

• Publisher: John Wiley and Sons
• Year: 2009
• Tongue: English
• Weight: 500 KB
• Volume: 206
• Category: Article
• ISSN: 0031-8965
• DOI: 10.1002/pssa.200880784

✦ Synopsis

Abstract

Al~0.25~Ga~0.75~N films were grown on a grooved‐Al~0.25~Ga~0.75~N/ AlN/sapphire template by MOVPE. The dislocation density on the grooved areas was as low as 1 × 10^8^ cm^–2^. We fabricated a UVA light‐emitting diode grown on such an AlGaN underlying layer exhibiting an output power of 12 mW at a DC current of 50 mA with a peak emission wavelength of 345 nm, which corresponds to an external quantum efficiency of 6.7%. This efficiency is the highest reported to date in this wavelength region. We also fabricated a 358 nm UVA laser diode (LD) using a GaN/AlGaN MQW active layer grown on an AlGaN underlying layer. This UV LD exhibits a threshold current of 73 mA and a corresponding current density of 3.8 kA/cm^2^ at 7 °C. The characteristic temperature T~0~ was 174 K in the temperature range of 7–27 °C. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)