Improving the photovoltaic performance of Zn2SnO4 solar cells by doping Sr2+/Ba2+ ions: Efficient electron injection and transfer

In the present study, the nanocrystalline Zn2SnO4 dopen with Sr2+/Ba2+ ions is synthesized via a hydrothermal method and their structure is analyzed in detail. Moreover, the photovoltaic properties of dye-sensitized solar cells composed of doped Zn2SnO4 are investigated. The enlarged energy difference between the conduction band edge of Zn2SnO4 and the lowest unoccupied molecular orbit (LUMO) of dye gives rise to the enhanced driving force for electron injection. The DSCs based on Sr2+/Ba2+ doped Zn2SnO4 improve the power efficiency through enhancing charge transport processes and reducing recombination rates. Compared to the photovoltaic conversion efficiency of pure Zn2SnO4 cells, the DSCs based on ZTO-Sr (3.0) exhibit a greater power conversion efficiency of 4.91%. As a consequence, the device of ZTO-Ba (1.5) also demonstrates an improved efficiency of up to 4.94%. This corresponds to an enhancement in power conversion efficiency of 17%, respectively, relative to control devices.