Construction of dye-sensitized solar cells using wet chemical route synthesized MoSe₂ counter electrode

This paper presents a simple and large area wet chemical preparation route for molybdenum diselenide (MoSe₂) atomic layers. MoSe₂ was synthesized onto fluorine doped tin oxide substrates and could be directly used as a counter electrode (CE) for dye-sensitized solar cells (DSSCs). The role of deposition time on the growth of MoSe₂ CE was elaborately discussed using Raman, X-ray diffraction and photoluminescence studies. Influence of wet chemical growth time on the surface modification of MoSe₂ CE was evidently demonstrated by scanning electron microscopy and atomic force microscopy studies. The MoSe₂ CE electrode has lower charge transfer resistance and superior electrocatalytic activity towards triiodide/iodide redox behavior, comparable to conventional Pt CEs. High power conversion efficiency of 7.28% was achieved, equivalent to scarce noble metal Pt CE (7.40%). Uniform surface morphology with active edge sites highly dominated to promote the superior electrocatalytic activity. This work opens a way to use an economical wet chemical method to fabricate the layered MoSe₂ CE as a replacement for high cost Pt based CE for DSSCs.