Enhanced photovoltaic performance and stability of dye-sensitized solar cells by utilizing manganese-doped ZnO photoanode with europium compact layer

Abstract

Zinc oxide (ZnO)-nanoparticles based photoanodes are one of the most important photoanodes in dye-sensitized solar cells (DSSCs). However, ZnO-based photoanodes have disadvantages such as low photovoltaic performance and low stability compared to titanium dioxide (TiO2)-nanoparticles based photoanodes. In this current work, two different strategies have been simultaneously applied to eliminate these disadvantages of ZnO photoanodes and to prepare more efficient photoanode for DSSCs applications. In the first strategy, europium (Eu) compact layer has been deposited between fluorine-doped tin oxide (FTO) substrate and ZnO paste in order to increase the current density of DSSCs by benefiting down-conversion and photoluminescence properties of Eu. In the second strategy, manganese (Mn) ions have been doped into the ZnO structure at different ratios in order to enhance the electron transport mechanism of the ZnO photoanode and to increase the stability of the obtained DSSCs. As a result of these two strategies, the obtained DSSC performance with 1.0 mol% Mn doping and Eu compact layer showed a conversion efficiency of 4.20%, which is much higher than pure ZnO DSSC photoanode employing (1.45%). More importantly, the device showed considerable stability and repeatability under the constant light for 3000 s. Considering this improved performance and stability of DSSCs, this work may guide different lanthanide compact layers and different doping sources in order to further improve the performance and stability of DSSCs.