Browsing by Author "Kuo, C. W."

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Efficiency Improvement of GaN-Based Light-Emitting Diode Prepared on GaN Nanorod Template
(2010-02-15)
Kuo, C. H.
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Chang, L. C.
;
Kuo, C. W.
;
Chi, G. C.
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光電工程學系
We demonstrated the formation of GaN-based nanorod (NR) structure by using self-assemble Ni nanoislands as the etching mask. It was found that crystal quality of the GaN epilayer prepared on an NR GaN template was significantly better than that prepared with a conventional low-temperature GaN nucleation layer. With the NR GaN template, it was found that 20-mA light-emitting diode (LED) output power can be enhanced by 39.8%, as compared to the conventional LED.
Influence on light-induced degradation in Cz-Si PERC cells under light soaking of variant wavelength and intensity
(2018-01-01)
Wu, Ching-Wen
;
Lee, Yen-Chun
;
Yu, Li-Chieh
;
Tsai, Min-An
;
Wu, Hung-Sen
We have carried out multiple analysis on the acceleration factors of LID for Cz-Si PERC cells, including temperatures, intensities and wavelengths at 396nmand 969nm. The recovery time of LID at 130 degrees C under 1 SUN shrinks down to 4 hrs and the maximum degradation in Pmax is less than 3 % due the elimination of B-O LID under high carrier-injection. However, it seems that higher intensities couldn't stop the second degradation from happening, indicating the formation of other defects. Therefore, we employ LED light source of different wavelengths and obtain that both maximum degradation of Pmax are quite different. The consequence implies that behavior of LID might be originated from the particular position (penetration depth) where carriers are located.
Study of InGaN-GaN Light-Emitting Diodes With Different Last Barrier Thicknesses
(2010-06-15)
Chen, Jun-Rong
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Lu, Tien-Chang
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Kuo, Hao-Chung
;
Fang, K. L.
;
Huang, K. F.
This work reports a theoretical and experimental study on the device performance of blue InGaN-GaN light-emitting diodes (LEDs) with different last barrier thicknesses. The experimental results show that the employment of a 25-nm-thick p-type GaN last barrier in GaN LEDs can improve the light output power from 35.6 to 40.2 mW at 50 mA. By using advanced device simulation, it is shown that the effective energy barrier created by the p-type AlGaN electron blocking layer (EBL) is significantly decreased due to the band bending at the interface between GaN last barrier and AlGaN EBL. The use of a p-type GaN last barrier before the growth of AlGaN EBL can provide a higher energy barrier to suppress the electron overflow and then enhance the light output power.