Solution Growth of BiSI Nanorod Arrays on a Tungsten Substrate for Solar Cell Application

One-dimensional nanostructure arrays hold great promise for orthogonalizing light absorption and carrier collection, and thus have been attractive building blocks for next-generation solar cells. Therefore, it is highly desired to build one-dimensional nanostructure arrays of novel photovoltaic materials. In this work, for the first time, the ternary BiSI nanorod arrays have been successfully fabricated on a tungsten substrate for application in solar cells. These nanorods have an oriented growth along the [001] direction. The UV–vis–NIR absorption results demonstrate that the prepared BiSI nanorods exhibit a continuous strong absorption in the entire visible light region with an indirect band gap of 1.57 eV. A solid-state solar-cell device utilizing the as-grown BiSI nanorod arrays as the n-type absorber layer and CuSCN as the p-type window layer is also developed. The assembled solar-cell device can reach a power conversion efficiency of 0.66% with a fill factor of 52.81%. Therefore, the present study reveals the potential of BiSI nanorod arrays as absorber materials for application in low-cost solar cells.