IEEE Photonics Journal (Jan 2020)

Improved Performance of Passive-Matrix Micro-LED Displays Using a Multi-Function Passivation Structure

  • Po-Wei Chen,
  • Po-Wen Hsiao,
  • Po-Chen Shen,
  • Hsuan-Jen Chen,
  • Yi-An Chen,
  • Ray-Hua Horng,
  • Dong-Sing Wuu

DOI
https://doi.org/10.1109/JPHOT.2020.3002554
Journal volume & issue
Vol. 12, no. 4
pp. 1 – 11

Abstract

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The enhanced light output efficiency of passive-matrix micro light-emitting-diode (LED) display was achieved by employing the tapered sidewalls and distributed-Bragg-reflector (DBR) passivation structure. The oblique angles at the bottom of multi-quantum wall and n-GaN are 48.9° and 21.8°, which can favor the planarization structure of pixel interconnection. As increasing the number of DBR (SiO2/TiO2) stacking from 3.5 to 5.5 pairs, the reflectance increased obviously from 81.4% to 98.0% at the wavelength of 450 nm. As the micro-LED display with a multi-function DBR structure, the output power of 1.07 mW under 1 mA, the external-quantum efficiency of 42% under 0.2 mA, and the luminance of 435 nits were obtained.

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