Systematic control of nanostructured interfaces of planar Sb₂S₃ solar cells by simple spin-coating process and its effect on photovoltaic properties

Herein, we report on the systematic engineering of the interface between the titanium oxide (TiO₂) photoelectrode and the antimony sulfide (Sb₂S₃) absorber layer in planar Sb₂S₃ solar cells, which was much unexplored, on the photovoltaic performance. Due to simple spin-coating process for the preparation of TiO₂ and Sb₂S₃ layers, it was possible to vary the interfacial conditions between the TiO₂ photoelectrode and the Sb₂S₃ absorber layer easily. Unlike conventional solar cells using mesoporous TiO₂ electrode, it was newly found that uniform and intimate contact between TiO₂ and Sb₂S₃ layers affects not only efficiency but also reproducibility of planar Sb₂S₃ solar cells. Our results clearly emphasize and raise the importance of interfacial engineering for the planar heterojunction solar cells.