Effect of internal surface area on the performance of $ZnO∕In2S3∕CuSCN$ solar cells with extremely thin absorber

Solar cells with an extremely thin light absorber were realized by wet chemical preparation on arrays of ZnO nanorods. The absorber consisted of an $In2S3$ layer (⁠$∼20nm$ thickness) and its interface region with a transparent CuSCN hole conductor. By changing the length of the nanorods $(0–3.3μm)$ and keeping the $In2S3$ layer thickness constant at $∼20nm$⁠, the short circuit current increased from about $2–10mA∕cm2$⁠. A marked increase of the external quantum efficiency at longer wavelengths is attributed to light scattering and a solar energy conversion efficiency of 2.5% has been demonstrated.