Improving the performance of Sb2Se3 thin-film solar cells using pyrolytic ammonium metatungstate back contact layer

Back surface recombination could have some adverse effects on superstrate antimony selenide (Sb 2 Se 3 ) solar cells. Anode interface modification, such as inserting a buffer layer with appropriate energy-level matching, is necessary. Here, a novel interfacial material, pyrolytic ammonium metatungstate (PAMT), prepared by spray pyrolysis deposition, was introduced to modify the back contract of antimony selenide solar cells. Morpho-structural and thermal analysis showed that this material is different from crystalline molybdenum oxide powder. Monology characterization showed that PAMT preferentially fills the space of the Sb 2 Se 3 grain boundary. The J–V test showed that this layer improved the interfacial contract between the absorber and the back electrode. The PAMT layer showed suitable energy matching with Sb 2 Se 3 , providing an effective channel for hole carriers transport from the absorber to the anode, and largely reducing back contact surface recombination. As a result, the PAMT-modified Sb 2 Se 3 device exhibited a much higher photovoltaic performance, significantly improving the efficiency from 5.27% to 6.11%. Graphical Abstract