Influence of barrier thickness modulation of InGaN/GaN MQW solar cells

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.