Browsing by Author "Liou, Fang-Jyun"

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Full-color micro-LED display with high color stability using semipolar (20-21) InGaN LEDs and quantum-dot photoresist
(2020-05-01)
Chen, Sung-Wen Huang
;
Huang, Yu-Ming
;
Singh, Konthoujam James
;
Hsu, Yu-Chien
;
Liou, Fang-Jyun
Red-green-blue (RGB) full-color micro light-emitting diodes (mu-LEDs) fabricated from semipolar (20-21) wafers, with a quantum-dot photoresist color-conversion layer, were demonstrated. The semipolar (20-21) InGaN/GaN mu-LEDs were fabricated on large (4 in.) patterned sapphire substrates by orientation-controlled epitaxy. The semipolar mu-LEDs showed a 3.2 nm peak wavelength shift and a 14.7% efficiency droop under 200 A/cm(2 )injected current density, indicating significant amelioration of the quantum-confined Stark effect. Because of the semipolar mu-LEDs' emission-wavelength stability, the RGB pixel showed little color shift with current density and achieved a wide color gamut (114.4% NTSC space and 85.4% Rec. 2020). (C) 2020 Chinese Laser Press
High-Bandwidth Green Semipolar (20-21) InGaN/GaN Micro Light-Emitting Diodes for Visible Light Communication
(2020-08-19)
Chen, Sung-Wen Huang
;
Huang, Yu-Ming
;
Chang, Yun-Han
;
Lin, Yue
;
Liou, Fang-Jyun
The light-emitting diode (LED) is among promising candidates of light sources in visible light communication (VLC); however, strong internal polarization fields in common c-plane LEDs, especially green LEDs, result in low frequency and limited transmission performance. This study aims to overcome the limited 3-dB bandwidth of long-wavelength InGaN/GaN LEDs. Thus, semipolar (20-21) micro-LEDs (mu LEDs) were fabricated through several improved approaches on epitaxy and chip processes. The mu LED exhibits a 525 nm peak wavelength and good polarization performance. The highest 3-dB bandwidth up to 756 MHz and 1.5 Gbit/s data rate was achieved under a current density of 2.0 kA/cm(2). These results suggest a good transmission capacity of green semipolar (20-21) mu LEDs in VLC applications.