TY - JOUR
T1 - Influence of AZO stair-like transparent layers on GaN-based light-emitting diodes
AU - Liou, Syuan Hao
AU - Tsai, Jung Hui
AU - Liu, Wen Chau
AU - Lin, Pao Sheng
AU - Chen, Yu Chi
N1 - Funding Information:
This work is supported by the Ministry of Science and Technology of the Republic of China under Contract Nos. MOST 106-2221-E-017-011 and 104-2221-E-017-007-MY2 .
Publisher Copyright:
© 2017 Elsevier Ltd
PY - 2017/10
Y1 - 2017/10
N2 - The GaN-based light-emitting diodes (LEDs) with various height ratios of aluminum-doped zinc oxide (AZO) stair-like transparent layers are fabricated and comparatively investigated. The characteristics of the LEDs with conventional plane AZO transparent layer (device A) and AZO stair-like transparent layers having height ratios of 1:1:1 (device B), 1.5:1:0.5 (device C), and 0.5:1:1.5 (device D) are compared. Attributed that the lower resistance is formed in the thinner AZO film of the stair-like structure, the current crowding effect is improved for extending the whole current-spreading area. Experimentally, the forward turn-on voltages of the LEDs are reduced from 3.68 V to 3.42 V as the plane AZO transparent layer is processed to form the stair-like transparent layers with height ratio of 1:1:1. In addition, the light luminous flux, output power, external quantum efficiency, and wall-plug efficiency of the device B are enhanced by 30.5, 12.1, 22.2, and 20.7%, respectively, as compared to the traditional device with plane AZO transparent layer.
AB - The GaN-based light-emitting diodes (LEDs) with various height ratios of aluminum-doped zinc oxide (AZO) stair-like transparent layers are fabricated and comparatively investigated. The characteristics of the LEDs with conventional plane AZO transparent layer (device A) and AZO stair-like transparent layers having height ratios of 1:1:1 (device B), 1.5:1:0.5 (device C), and 0.5:1:1.5 (device D) are compared. Attributed that the lower resistance is formed in the thinner AZO film of the stair-like structure, the current crowding effect is improved for extending the whole current-spreading area. Experimentally, the forward turn-on voltages of the LEDs are reduced from 3.68 V to 3.42 V as the plane AZO transparent layer is processed to form the stair-like transparent layers with height ratio of 1:1:1. In addition, the light luminous flux, output power, external quantum efficiency, and wall-plug efficiency of the device B are enhanced by 30.5, 12.1, 22.2, and 20.7%, respectively, as compared to the traditional device with plane AZO transparent layer.
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U2 - 10.1016/j.spmi.2017.08.047
DO - 10.1016/j.spmi.2017.08.047
M3 - Article
AN - SCOPUS:85028510292
SN - 0749-6036
VL - 110
SP - 171
EP - 179
JO - Superlattices and Microstructures
JF - Superlattices and Microstructures
ER -