Abstract: Currently, SnO2(Tin Dioxide) has become the most commonly used material for the electron transport layer in high-performance PSCs(Perovskite Solar Cells). A strategy for optimizing SnO2 using a small-molecule chelator is proposed to address the problem of agglomeration-prone commercial SnO2 aqueous dispersions and the need to enhance the electrical and surface properties of SnO2 films. The PSCs with the device structure of ITO/ SnO2+SC / FA1-x MAx PbI3 / Spiro-OMeTAD/ Au are prepared by doping the SnO2 transport layer with a low-cost chelator, SC( Sodium Citrate). After the introduction of SC with an optimized concentration, the open-circuit voltage and fill factor of PSCs can reach up to 1. 135 V and 78. 23% , respectively, with a power conversion efficiency of 21. 53% . This represents a significant improvement compared to the devices without the introduction of SC. The characterization of the films and devices revealed that the doping of SC could enhance the electrical and surface properties of the SnO2 films, which in turn improves perovskite crystallization. As a result, defects in the device are reduced, recombination loss is lowered, and charge transport is promoted.

Key words: perovskite solar cells, tin dioxide, crystallization, defects, recombination loss, charge transport