标题：Broadband enhancement of coaxial heterogeneous gallium arsenide single-nanowire solar cells
作者：Xiaofeng Li*, Yaohui Zhan and Chinhua Wang
摘要：
Coaxial gallium arsenide single-nanowire solar cells with multiple electrically and optically functional nanoshells are presented in this paper.Both optical absorption and light-conversion characteristics are extensively examined by performing a comprehensive device-orientedsimulation. It is found that a window layer with a large semiconductor bandgap is necessary for the nanowire gallium arsenide solar cells,which allow internal quantum efficiency ~100% in ~75% of the absorption band of gallium arsenide. Results also reveal the role ofnanofocusing effect in enhancing the performance of nanowire devices that show both absorption and external quantum efficiencies over 100%under resonances. A dielectric cladding shell is introduced and optimized, which enhances the nanofocusing effect and leads to extraordinaryenhancement of both absorption and light-conversion capabilities in a very broad band. This design contributes a short-circuit current densityincreased by 2.4 times and an open-circuit voltage over 1.1 V.