Photoelectric Properties of High Power GaN Based LEDs on Cu/Cr Composite Substrates

Abstract

The thermal problems of high power LEDs could be solved effectively and the stability of the device could be also improved, employing metal substrates for high power LEDs. In this paper,high power GaN based blue LEDs on metal substrates were successfully prepared by transferring GaN-based LED epitaxial film on Si (111) substrates to the Cu/Cr composite substrates employing electroplating method. The forward voltage of the as-prepared LEDs was 3.4 V, when the forward operating current was 350 mA, which was similar with the level of market products. The corresponding voltage could reach 25 V when reverse current was 10 μA, better than the level of market products. It showed good anti-saturation property when forward current varied from 0 mA to 1200 mA. The stability of wavelength vs current was also favourable, which the peak wavelength shifted to long wavelength about 1nm in the test range of 10 mA to 1200 mA.