Perovskite film-wire transformation: Preparation, characterization and device application

Abstract In this research, we demonstrate regular-type perovskite solar cells based on tungsten trioxide nanoparticles layer (WO 3 NL) as the electron transport layer and methylammonium lead iodide nanowires (MAPbI 3 NWs) as the absorbing layer. By adjusting the amount of the anti-solvent DMF, MAPbI 3 NWs with different diameters ranging from 50 to 100 nm and lengths extending to several micrometers were obtained. [6,6]-phenyl-C 61 -butyric acid methyl ester (PCBM) and cesium carbonate (Cs 2 CO 3 ) were introduced between WO 3 NL and MAPbI 3 NWs to improve film morphology and charge transfer ability. Meanwhile, spiro-MeOTAD doped with bis(trifluoromethane)sulfonimide lithium salt (Li-TFSI) was utilized to enhance hole transport. Finally, the perovskite solar cells with the configuration of ITO/WO 3 NL/Cs 2 CO 3 /PCBM/MAPbI 3 NWs/spiro-MeOTAD/Au were fabricated and evaluated. To date, perovskite NWs treating with the proper amount of the anti-solvent DMF possess higher absorption, faster carrier transportation and lower recombination that are responsible for photovoltaic application.