High-performance dye-sensitized solar cells based on Ag-doped SnS2counter electrodes

Tin disulfide (SnS2) has been considered as a prospective counter electrode (CE) material for dye-sensitized solar cells due to its good electrocatalytic properties. However, its low electronic and ionic conductivities pose challenges for using it in high-performance dye-sensitized solar cells (DSSCs). Herein, doping is utilized to improve the properties of SnS2 for application as a DSSC counter electrode. Ag-doped SnS2 samples with various doping amounts are prepared via a facile one-step solvothermal route. It is found that the DSSC based on a 5% Ag-doped SnS2 CE demonstrates the best performance showing an impressive photovoltaic conversion efficiency (PCE) of 8.70% which exceeds the efficiency of a Pt-based DSSC (7.88%) by 10.41%, while the DSSC consisting of undoped SnS2 only exhibits a PCE of 6.47%. Such an enhanced efficiency of the DSSC is attributed to the effectively improved electrocatalytic activity and mixed conductivity resulting from the Ag dopant. Therefore, the Ag-doped SnS2 CE proves to be a promising alternative to the expensive Pt CE in DSSCs and may pave a new way for large-scale production of new-generation DSSCs.