Institution: | a Research Institute of Electrical Engineering, National Tsing Hua University, Hsinchu 30043, Taiwan, ROC b Integrated Optoelectronics, Applied Research Laboratory, Telecommunication Laboratories, Chunghwa Telecom Co., Yang-Mei 32617, Taiwan, ROC |
Abstract: | In this article, we investigate the influence of AlGaAs and GaP window layers on the device performance of 650 nm AlGaInP/GaInP multi-quantum-well (MQW) light-emitting diodes (LEDs) grown by metalorganic chemical-vapor deposition. The AlGaInP/GaInP MQW structure with different window layers are characterized by double-crystal X-ray diffraction, secondary ion mass spectrometry and photoluminescence. By using the AlGaAs window layer, the LEDs have a lower cut-in voltage, a smaller dynamic series resistance and a higher breakdown voltage, while the LEDs with a GaP window layer show a stronger electroluminescence intensity, a higher light output power, a higher external quantum efficiency and a slower degradation of light output with increasing bias current. These results indicate that the GaP material is more adequate to be used as a window layer for the AlGaInP optical devices. |