Abstract: Aiming at the large number of defects at the electron transport layer/ perovskite layer interface of perovskite solar cells, an optimized strategy employing an inorganic salt for interface passivation is proposed. This strategy selects low-cost LiCl(Lithium Chloride) as the interface passivation material between the electron transport layer and perovskite layer, and prepares the perovskite solar cell with the device structure of ITO/ TiO₂ / LiCl / CH₃NH₃PbI₃ / spiro-OMeTAD/ Ag. After the introduction of LiCl with an optimized concentration, the short- circuit current density and fill factor of the perovskite solar cell achieve 21. 05 mA/ cm ² and 72. 55% , and the energy conversion efficiency is 16. 95% , which shows an increase of 23. 00% compared with the device without the introduction of LiCl. After characterizing the device and the film, it is found that LiCl can passivate the defects and traps at the interface and increase the conductivity of TiO₂ , thereby reducing the interface recombination loss and promoting the charge transport.

Key words: perovskite solar cells; , interface passivation; , defects; , conductivity; , interface recombination; , charge transport