Improving the stability and scalability of all-inorganic inverted CsPbI2Br perovskite solar cell

The ultrathin Ti 0.9 Sn 0.1 O 2 nanocrystals have greatly improved interface contact due to the facile film formation, good conductivity and high work function. The all-inorganic inverted NiO x /CsPbI 2 Br/Ti 0.9 Sn 0.1 O 2 p-i-n device shows a power conversion efficiency of 14.0%. All-inorganic perovskite solar cells (PSCs) have potential to pass the stability international standard of IEC61215:2016 but cannot deliver high performance and stability due to the poor interface contact. In this paper, Sn-doped TiO 2 (Ti 1− x Sn x O 2 ) ultrathin nanoparticles are prepared for electron transport layer (ETL) by solution process. The ultrathin Ti 0.9 Sn 0.1 O 2 nanocrystals have greatly improved interface contact due to the facile film formation, good conductivity and high work function. The all-inorganic inverted NiO x /CsPbI 2 Br/Ti 0.9 Sn 0.1 O 2 p-i-n device shows a power conversion efficiency (PCE) of 14.0%. We tested the heat stability, light stability and light-heat stability. After stored in 85 °C for 65 days, the inverted PSCs still retains 98% of initial efficiency. Under continuous standard one-sun illumination for 600 h, there is no efficiency decay, and under continuous illumination at 85 °C for 200 h, the device still retains 85% of initial efficiency. The 1.0 cm 2 device of inverted structure shows a PCE of up to 11.2%. The ultrathin Ti 1− x Sn x O 2 is promising to improve the scalability and stability and thus increase the commercial prospect.