Scalable Low‐Cost SnS2 Nanosheets as Counter Electrode Building Blocks for Dye‐Sensitized Solar Cells

A new type of semitransparent SnS₂ nanosheet (NS) films were synthesized using a simple and environmentally friendly solution‐processed approach, which were subsequently used as a counter electrode (CE) alternative to the noble metal Pt for triiodide reduction in dye‐sensitized solar cells (DSSCs). The resultant SnS₂‐based CE with a thickness of about 300 nm exhibited excellent electrochemical catalytic activity for catalyzing the reduction of triiodide and demonstrated comparable power conversion efficiency of 7.64 % with that of expensive Pt‐based CE in DSSCs (7.71 %). When functionalized with a small amount of carbon nanoparticles, the SnS₂ NS‐based CE showed even better performance of 8.06 % than Pt under the same conditions. Considering the facile fabrication method, optical transparency, low cost, and remarkable catalytic property, this study on SnS₂ NSs may shed light on the large‐scale production of electrocatalytic electrode materials for low‐cost photovoltaic devices.