Influence of AZO stair-like transparent layers on GaN-based light-emitting diodes

Syuan Hao Liou, Jung Hui Tsai, Wen Chau Liu, Pao Sheng Lin, Yu Chi Chen

Research output: Contribution to journalArticlepeer-review

1 Citation (Scopus)


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.

Original languageEnglish
Pages (from-to)171-179
Number of pages9
JournalSuperlattices and Microstructures
Publication statusPublished - 2017 Oct

All Science Journal Classification (ASJC) codes

  • Materials Science(all)
  • Condensed Matter Physics
  • Electrical and Electronic Engineering


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