The Characteristics of High Power LED at Low and High Temperature

In this paper,the high power GaN-based white and blue light-emitting diodes (LEDs) and AlGaInP-based red and yellow LEDs are fabricated and the electrical and optical properties at low and high temperature are measured.The temperature dependence of forward voltage,relative luminous intensity,wavelength,color temperature of different LEDs are analyzed.Experiment result shows that temperature has great influence on electrical and optical proprieties of high-power LEDs.When the forward voltage increased and peak wavelength blue-shift was observed with decreasing temperature.At high temperature,the optical power of LEDs decreases rapidly and the peak wavelength becames red-shift.