Perovskites fabricated with volatile anti-solvents for more efficient solar cells.

Abstract In this paper, we introduce several kinds of volatile anti-solvents to prepare a fully-reacted perovskite film, thereby obtaining a high-efficiency solar cell. The volatility of the solvent strongly influences the uniformity and porosity of the PbI 2 film, and thus affects the uniformity and compactness of the obtained perovskite film. Scanning electron microscopy (SEM) revealed that the perovskite film fabricated by the ethanol treatment method was very dense and exhibited a smoother surface. At the same time, the compositions of the perovskite films produced using different volatile solvents were determined via X-ray diffraction (XRD), and it was found that the film fabricated by the ethanol treatment method completely reacted with no residual PbI 2. The ethanol treated sample was characterized by UV–vis spectroscopy and current density-voltage (J-V) measurements, and the best absorbance, a fill factor of 0.73, short circuit current density, J sc , of 22.1 mA cm-2, an open circuit voltage, V oc , of 1.04 V and a photoelectric conversion efficiency, PCE, of 16.8% were obtained. Graphical abstract Image 1 Highlights • Conventional method produces residual PbI 2. • Residual PbI 2 deteriorates solar cell photoelectric performance. • Ethanol removes residual PbI 2. [ABSTRACT FROM AUTHOR]