Facilitating the formation of SnO2 film via hydroxyl groups for efficient perovskite solar cells

Interfacial engineering has been considered as an effective technique to improve the photovoltaic performance of perovskite solar cells (PSCs). Here, interface between tin oxide (SnO2) film and fluorine-doped (FTO) glass is dealt with a piranha solution, resulting in more hydroxyl groups on surface FTO glass. SnO2 fabricated by spin-coating SnCl2·2H2O precursor. Our results demonstrate that exhibits high electrical conductivity, low electron trap density, suitable energy level. Furthermore, roughness beneficial fabricate high-quality film. Then, PSCs structure FTO/SnO2/Cs0.05(MA0.17FA0.83)0.95Pb(I0.83Br0.17)3/Spiro-OMeTAD/Au are also fabricated. The highest power conversion efficiency (PCE) increases from 18.28% 19.51%, average PCE enhances 17.82% 18.89%. optimized PSC shows long-term stability remains 97% its initial after 4000 h on-shelf lifetime test.