Open AccessEnhanced light-harvesting capability for silicon single-nanowire solar cells coupled with metallic cavity
Author(s) -
Feng Gai,
Cheng Zhang,
Yaohui Zhan,
Xiao Feng Li
Publication year - 2016
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.24.0a1505
Subject(s) - materials science , nanowire , optoelectronics , photocurrent , optics , dispersion (optics) , trapping , absorption (acoustics) , antenna (radio) , silicon , physics , ecology , telecommunications , computer science , composite material , biology
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.