Hydrothermally Deposited Antimony Sulfide Solar Cells with $\mathrm{V}_{\text{OC}}$ Approaching 800 mV

Antimony sulfide $(\text{Sb}_{2}\mathrm{S}_{3})$ represents an emerging thin-film photovoltaic light-absorber, with potential as a wide gap top cell for high-efficiency tandem devices. Here, we report the development and characterization of $\text{Sb}_{2}\mathrm{S}_{3}$ absorber layers prepared by the hydrothermal method. Completed devices based on chemical bath deposited cadmium sulfide (CdS) and Spiro-OMeTAD as the electron-and hole-transport layers, respectively, have yielded promising power conversion efficiencies as high as 5.5 %. Although the typical deficit reported between the Sb ${}_{2}\mathrm{S}_{3}$ bandgap energy and the open-circuit voltage $(\mathrm{V}_{\text{OC}})$ remains high, we report high Voc values approaching 800 mV.