Sn-doped TiO2 coated zinc oxide nanorods as electron transport layer in perovskite solar cells

For commercialization and enhancement of applicability, the development of electron transport layer (ETL) and its interface for low temperature processes and efficient charge transfer are very important. Earlier ZnO has been reported as excellent material for ETL, however the unstable chemical compatibility of ZnO with perovskite layers, thus making it challenging to acquire higher efficiency in solar cells. The present paper has proposed the concept of doping ZnO nanorods with Sn and coating with TiO2. The cell metrics were investigated for ETL thickness varying from 0 to150 nm and perovskite thickness (0-800 nm). From contour plots, it is evident that the fill factor and efficiency were found higher 0.88 and 29.8% till 35 nm of ETL thickness, however afterwards both drops to zero because of rise in value of series resistance. Another parameters involving short circuit current density and open circuit voltage hold on consistency till 100 nm of ETL thickness and then started attenuating towards zero and 0.48 at ETL thickness of 150 nm. The present findings have shown that doping and coating ZnO nanorods with Sn and TiO2, respectively, made ZnO more promising candidate as ETL in designing efficient solar cells.