Light trapping in four-coupled silicon nanowires for photovoltaic applications

Silicon nanowires (SiNW) are highly cost-effective and efficient materials, widely applied in solar cells. In this work, we report four-coupled SiNWs (FCNW) for photovoltaic applications. We found that FCNW shows significantly enhanced light absorption compared to single SiNW (SNW) and four-uncoupled SiNWs (FUNW), due to its excellent light-trapping effect. The optimal short-circuit current density of FCNW reaches 14.10 mA/cm², increasing by 41.71 % and 17.99 % compared to SNW (9.95 mA/cm²) and FUNW (11.95 mA/cm²) respectively. Moreover, coating a non-absorbing dielectric shell (SFCNW) and adjusting its radius can further improve the short-circuit current density. The results show that SFCNW possesses a higher short-circuit current density of 22.19 mA/cm², enhanced by 123.02 % and 57.38 % relative to SNW and FCNW respectively. Therefore, the SFCNW structure provides a novel approach to improving the photoelectric conversion efficiency of solar cells.