Solution processed NiOx hole-transporting material for all-inorganic planar heterojunction Sb2S3 solar cells

Abstract Light-harvesting material Sb 2 S 3 has recently attracted tremendous attention due to its excellent photovoltaic properties. Extensive efforts have been exerted to improve the power conversion efficiency through process innovation, interface modification and band gap engineering. In this study, we report an all-inorganic planar heterojunction Sb 2 S 3 solar cell using NiO x as hole extraction material, which is deposited from preformed NiO x nanoparticle solution. We demonstrate that the device performance can be significantly enhanced upon O 2 plasma treatment on NiO x layer. As a result, O 2 plasma-treated NiO x hole conductor leads to a 43% enhancement in power conversion efficiency when compared to untreated one, delivering an efficiency of 3.51%. The enhancement mechanisms are interpreted in terms of electronic structures and interfacial charge transport properties characterized by synchrotron-based high resolution ultraviolet photoelectron spectroscopy and electrochemical impedance spectroscopy. This work provides a choice of novel inorganic hole-transporting material for the preparation of stable and efficient all-inorganic solar cell device based on Sb 2 S 3 as well as Sb 2 (S,Se) 3 .