Gai Feng, Zhang Cheng, Zhan Yaohui, Li Xiaofeng
Opt Express. 2016 Dec 26;24(26):A1505-A1513. doi: 10.1364/OE.24.0A1505.
Single-nanowire solar cells (SNSCs) are attracting increasing interest due to their unique optical antenna effect beneficial for achieving higher light-trapping capability. However, for conventional circular-cross-sectional SNSCs, the light-trapping performance is still far from the expectation. Here we demonstrate that integrating a silicon single nanowire into a metallic slit can dramatically enhance the absorption efficiency over almost the whole spectral band due to strengthened optical antenna effect. Especially, it is found that by using finite-size metallic blocks to form a nanoscale metallic cavity, the light-trapping performance of the SNSCs can be further improved. Through examining the detailed optical spectral response, electric field distribution, and cavity dispersion characteristics, the metallic-coupled SNSC system is optimized and the underlying physics are provided. Simulation results indicate that the photocurrent density of the SNSCs coupled with the designed metallic cavity can be enhanced by 44.4% than that of the conventional bare SNSCs.
单纳米线太阳能电池（SNSCs）因其独特的光学天线效应有利于实现更高的光捕获能力而受到越来越多的关注。然而，对于传统的圆形横截面SNSCs，其光捕获性能仍远未达到预期。在此，我们证明将硅单纳米线集成到金属狭缝中，由于光学天线效应增强，几乎可以在整个光谱波段显著提高吸收效率。特别是，发现通过使用有限尺寸的金属块形成纳米级金属腔，SNSCs的光捕获性能可以进一步提高。通过详细研究光谱响应、电场分布和腔色散特性，优化了金属耦合SNSC系统并给出了其潜在物理机制。模拟结果表明，与设计的金属腔耦合的SNSCs的光电流密度比传统的裸SNSCs提高了44.4%。
