High power nitride based light emitting diodes with Ni/ITO p-type contacts

Abstract

Large size (i.e. 1 mm × 1 mm) high power nitride-based light emitting diodes (LEDs) with Ni/Au and Ni/indium tin oxide (ITO) p-contacts were fabricated. It was found that the 200 mA forward voltage was 3.19 and 3.3 V for the power LEDs with Ni/Au and Ni/ITO p-contacts, respectively. On the other hand, although the 200 mA output power was only 11.59 mW for the power LED with Ni/Au p-contact, the 200 mA output power could reach 16.52 mW for the power LED with Ni/ITO p-contact. Such a significant increase could be attributed to the more transparent nature of Ni/ITO, as compared to Ni/Au. Preliminary life test also indicates that power LEDs with Ni/ITO p-contact are at least as reliable as power LEDs with Ni/Au p-contact. © 2003 Elsevier Science Ltd. All rights reserved.