Over 200 mW on 365 nm ultraviolet light emitting diode of GaN‐free structure

• Published in: Physica status solidi. A, Applied research Applied research, 2003-11, Vol.200 (1), p.114-117
• Main Authors: Morita, Daisuke, Sano, Masahiko, Yamamoto, Masashi, Nonaka, Mitsuhiro, Yasutomo, Katsuhiro, Akaishi, Kazuyuki, Nagahama, Shin‐ichi, Mukai, Takashi
• Format: Article
• Language: English
• Subjects: 78.60.Fi; 81.05.Ea; 85.60.Jb
• ISSN: 0031-8965; 1610-1634; 1521-396X
• DOI: 10.1002/pssa.200303395

We have remarkably improved the emission efficiency of 365 nm ultraviolet (UV) light emitting diode (LED). Rugged pattern is fabricated on the surface of LED chips in order to enhance the extraction efficiency. As a result, the extraction efficiency of this LED approximately increased by 50%. When this UV LED was operated at a forward‐bias pulsed current of 500 mA at room temperature (RT), the peak wavelength, the output power (Po), the operating voltage (Vf) and the external quantum efficiency (ηex) were 365 nm, 240 mW, 4.5 V and 14.1%, respectively. On the other hand, at a forward‐bias direct current of 500 mA at RT, Po, Vf and ηex were 210 mW, 4.3 V and 12.4%, respectively. The ηex at 365 nm increased to double that of the reported value before. (© 2003 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)