SnO2@ZnO nanocomposites doped polyaniline polymer for high performance of HTM-free perovskite solar cells and carbon-based

Abstract Herein, at first, green SnO 2 @ZnO nanocomposites were synthesized using Calotropis plant extract as an electron transfer material (ETM) to fabricate low-temperature-processed perovskite solar cells (PSCs). Then, the polyaniline (PANI) polymer was applied as an efficient additive to improve perovskite film quality. Under the effects of the small content of PANI additive, the quality of perovskite films is enhanced, which showed higher crystallinity in (110) crystal plane; also, the perovskite grains were found to be enlarged from 342 to 588 nm. The power conversion efficiency (PCE) of the prepared PSCs with SnO 2 @ZnO.PANI nanocomposites electron transfer layer (ETL) increased by 3.12%, compared with the PCE of SnO 2 @ZnO nanocomposites. The perovskite devices using SnO 2 @ZnO.PANI nanocomposites ETL have shown good stability during 480 h of tests. Furthermore, the optimal PSCs were fabricated by the mp-TiO 2 /SnO 2 @ZnO.PANI nanocomposites as ETL, which has a power conversion efficiency of 15.45%. We expect that these results will boost the development of low-temperature ETL, which is essential for the commercializing of high-performance, stable, and flexible perovskite solar cells.