Browsing by Author "Hsieh, Chi-Chang"

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Influence of barrier thickness modulation of InGaN/GaN MQW solar cells
(2013)
Hsieh, Chi-Chang
;
Lai, Fang-, I
;
Wang, Hsun-Wen
;
電子物理學系
;
Department of Electrophysics
The influence of band structure and indium composition of stepping layer are numerically investigated on the photovoltaic characteristics of InGaN/GaN MQW solar cell. In this study, the barrier structure and indium composition of inserting stepping layer leads to a substantial influence in the cell efficiency and output short circuit current density. It reveals that L-structure in barrier modulation would contribute to fine carrier collection and increase the conversion efficiency. Moreover, L-structure barrier modulation would effectively reduce the recombination rate in wells near p-GaN side where dominant recombination in well regions is. Barrier height of stepping layers plays an important role in high carrier collection that keeps high conversion efficiency. However, the optimal 5% indium composition of L-structure 14-pair MQW solar cell would obtain the best performance.
Numerical Study of In0.15Ga0.85N/GaN MQW Solar Cells with varying well band structure
(2013)
Wang, Hsun-Wen
;
Hsieh, Chi-Chang
;
Lai, Fang-I
;
Lin, Shiuan-Huei
;
Kuo, Hao-Chung
The photovoltaic properties of 14 pairs In0.15Ga0.85N/GaN multiple quantum well solar cells with varying indium composition of QW are investigated numerically. The simulation results show that smooth well structure of energy band can be reduce carrier confinement and the recombination to enhance photo-current generation. This helpful design is easy to improve carrier transport to collection. And the optimal In0.15Ga0.85N/GaN MQW solar cell had V-oc of 2.37V, J(sc) of 0.73, and the efficiency of 0.79%, which the efficiencies is enhanced 69.2 % to reference cell.