High efficiency perovskite solar cells via NaCl modified tin oxide electron transport layer

The SnO2 electron transport layer (ETL) has been proved to play an important role on the charge extraction and recombination for high efficiency perovskite solar cells (PSCs). We fabricated added sodium chloride (NaCl) modification of SnO2 ETL with optimal concentration, and achieved a high photoelectric conversion efficiency (PCE) of 21.2% with nearly 20% improvement. It was demonstrated that the addition of NaCl effectively enhanced the charge transfer between the ETL and perovskite, suppressed the non-radiative recombination in the interface. Particularly, it exhibited markedly improved open-voltage and fill factor. This simple modified strategy provides a practical and fast method to improve the performance of high efficiency PSCs.