COMBINATORIAL STUDY OF NICKEL-GOLD P-CONTACTS FOR BLUE INDIUM GALLIUM NITRIDE LIGHT-EMITTING DIODES

摘要

Although the efficiency of the Gallium Nitride (GaN) Light Emitting-Diode (LED) has improved in the past decade, a great opportunity for further efficiency improvement lies in the optimization of the Nickel-Gold composition of the p-type GaN metal contacts. The work described here will analyze the properties and performance of LED p-type contacts with varying Nickel-Gold (Ni-Au) compositions. In this work, during the electron-beam deposition of the Ni and Au onto an LED wafer, the relative thicknesses of the two metals were spatially varied to provide a combinatorial array of Ni and Au compositions on a single LED wafer. Each Ni-Au composition on the LED wafer was then analyzed for optical transmittance before and after annealing. LED devices were finally fabricated from the wafer, and the resultant overall power efficiencies of the fabricated LED devices were evaluated as a function of Ni and Au thickness.