title: Fabrication and characterization of GaN-based light-emitting diodes without pre-activation of p-type GaN.
abstract: We fabricated GaN-based light-emitting diodes (LEDs) without pre-activation of p-type GaN. During the fabrication process, a 100-nm-thick indium tin oxide film was served as the p-type contact layer and annealed at 500°C in N2 ambient for 20 min to increase its transparency as well as to activate the p-type GaN. The electrical measurements showed that the LEDs were featured by a lower forward voltage and higher wall-plug efficiency in comparison with LEDs using pre-activation of p-type GaN. We discussed the mechanism of activation of p-type GaN at 500°C in N2 ambient. Furthermore, x-ray photoemission spectroscopy examinations were carried out to study the improved electrical performances of the LEDs without pre-activation of p-type GaN.
authors: Engineering Research Center for Optoelectronics of Guangdong Province, School of Physics and Optoelectronics, South China University of Technology, Guangzhou, Guangdong 510640 China.
authors: Xiao-Long
authors: XL
authors: Hu
authors: Engineering Research Center for Optoelectronics of Guangdong Province, School of Physics and Optoelectronics, South China University of Technology, Guangzhou, Guangdong 510640 China.
authors: Hong
authors: H
authors: Wang
authors: Engineering Research Center for Optoelectronics of Guangdong Province, School of Physics and Optoelectronics, South China University of Technology, Guangzhou, Guangdong 510640 China.
authors: Xi-Chun
authors: XC
authors: Zhang
keywords: Hall effect; Indium tin oxide; Light-emitting diodes; p-type GaN