Enhanced performance of mesostructured perovskite solar cells with a composite Sn4+-doped TiO2 electron transport layer.

Recently, perovskite solar cells (PSCs) have attracted more attention. TiO₂ as the most common electron transfer material in PSCs has been improved by a serious of methods. In this study, a simple method was used to improve the traditional compact TiO₂ properties by doping with Sn⁴⁺. It demonstrated that the conductivity of the TiO₂ film could be well improved and the band-gap shifted from 3.65 to 3.55 eV with the introduction of Sn ions. The Sn–O–Ti bond was observed in the Sn:TiO₂ film according to the results of XPS. The mesostructured PSCs based on Sn:TiO₂ exhibited negligible J-V hysteresis behavior, and the J_sc of the device increased distinctly. The power conversion efficiency (PCE) of the Sn:TiO₂ device was improved from 14.86 to 17.11%, compared with the reference device. [ABSTRACT FROM AUTHOR]