《Temperature dependence of light-output performance of InGaN-GaN MQW Well-LED》.pdf

Temperature dependence of light-output performance of InGaN/GaN multiple-quantum well light-emitting diodes with various In compositions Chul Huh,* William J. Schaff, Lester F. Eastman, and Seong-Ju Parka School of Electrical and Computer Engineering, Cornell University, Ithaca, NY 14853 aDepartment of Materials Science and Engineering, Kwangju Institute of Science and Technology, Kwangju 500-712, Korea ABSTRACT We have investigated the temperature dependence of electrical and output performance of InGaN/GaN multiple-quantum well (MQW) light-emitting diodes (LEDs) with different indium compositions in the InGaN/GaN MQWs. With increasing In composition in the MQWs, the output performance of the LEDs at room temperature was increased due to a deeper potential barrier for the carriers to escape from the MQWs and the localized energy states caused by a In composition fluctuation in MQWs. However, it was found that the output performance depends on the In composition in InGaN/GaN MQWs with increasing temperature from room temperature. With increasing temperature, the output power for LED with a relatively higher In composition in the MQWs was decreased more rapidly compared to that of LED with a lower In composition in the MQWs due to the increased nonradiation recombination through the high defect densities in the MQWs resulted from the increased accumulation of strain between InGaN well and GaN barrier. Keywords: InGaN/GaN multiple-quantum well, light-emitting diode, emission peak wavelength, output power, temperature coefficient