Browsing by Author "Chang, Ruey-Wen"

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Enhanced Light Output Power and Growth Mechanism of GaN-Based Light-Emitting Diodes Grown on Cone-Shaped SiO2 Patterned Template
(2013-04-01)
Lin, Da-Wei
;
Huang, Jhih-Kai
;
Lee, Chia-Yu
;
Chang, Ruey-Wen
;
Lan, Yu-Pin
In this study, we successfully transferred the patterns of a cone-shaped patterned sapphire substrate (CPSS) into SiO2 layer to fabricate a cone-shaped SiO2 patterned template by using nanoimprint lithography (NIL). The GaN-based light-emitting diodes (LEDs) were grown on this template by metal-organic chemical vapor deposition (MOCVD). The transmission electron microscopy (TEM) images suggest that the stacking faults formed near the cone-shaped SiO2 patterns during the epitaxial lateral overgrowth (ELOG) can effectively suppress the threading dislocations, which results in an enhancement of internal quantum efficiency. The Monte Carlo ray-tracing simulation reveals that the light extraction efficiency of the LED grown on cone-shaped SiO2 patterned template can be enhanced as compared with the LED grown on CPSS. As a result, the light output power of the LED grown on cone-shaped SiO2 patterned template outperformed the LED grown on CPSS.
Highly Efficient InGaN-based LED with Embedded Cubic Airvoids
(2014)
Lin, Da-Wei
;
Huang, Jhih-Kai
;
Liu, Che-Yu
;
Chang, Ruey-Wen
;
Wang, Sheng-Wen
Highly efficient InGaN-based LEDs with embedded sidewall passivation cubic airvoids made by nanoimprint lithography were demonstrated. The LEDs with embedded airvoids exhibit a 45% enhancement of light output at 20 mA compared with conventional LEDs.
The Crystalline and Optical Properties of (11(2)over-bar2) Semipolar GaN and InGaN/GaN MQWs on (1(1)over-bar00) M-Sapphire
(2013-01-01)
Li, Yun-Jing
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Chang, Shih-Pang
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Sou, Kuok-Pan
;
Chang, Jet-Rung
;
Chang, Ruey-Wen
We report the growth temperature effect on the crystalline and optical properties of (11 (2) over bar2) semipolar GaN and InGaN/GaN MQWs. It shows that a lower growth temperature at 1020 degrees C produces better crystalline and optical properties.