Nitride-Based LEDs With High-Reflectance and Wide-Angle Ag Mirror${+}$SiO$_{2}$/TiO$_{2}$ DBR Backside Reflector

Abstract

Nitride-based light-emitting diodes (LEDs) with a backside reflector combining a SiO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> /TiO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> distributed Bragg reflector (DBR) and an Ag mirror were simulated and fabricated. With combining the three-pair SiO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> /TiO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> DBR and an Ag mirror, it was found that we can significantly enhance the 96% reflectance of Ag mirror to 99.1% with an incident angle of 0°. Furthermore, reflectance of the proposed reflector depends slightly on incident light wavelength and the incident angle. With 350-mA current injection, it was found that the output powers were 122, 138, 153, 156, and 162 mW for the LEDs without reflector, with an Al mirror, with Al +3DBR mirror, with an Ag mirror, and with Ag+3DBR mirror, respectively.