Abstract：In recent years, thin film solar cells with perovskite materials as light absorbers have attracted increased attention. The power conversion efficiencies (PCE) of organic lead-halide perovskite solar cells have reached 23% in ten years, resulting from perovskite absorber material with high absorption coefficient, suitable and adjustable bandgap, long carrier diffusion length. In 2016, GrtzelL introduced a simple vacuum-flash solution processing method (VFSP) to obtain FA and MA mixed perovskite film with high quality. Compared with other traditional solution processing methods, VFSP paved the way to realize high-PCE and large-area perovskite solar cells. In this work, the perovsikte films were fabricated by VFSP, and scanning electron microscopy (SEM), X-ray diffraction (XRD), absorption and photoluminescence spectra were used to investigate the morphology, structure and optical properties. The results showed that this method can be used to prepared uniform and pinhole-free perovskite films with FA-, Br and Cl-doping, including (FAPbI3)0.85(MAPbBr3)0.15, MAPbI3 and MAPb(IxCl1-x)3. The crystal grain sizes were 500, 100 and 200 nm, respectively. The growing process of the film was that the intermediate-phase was formed during the vacuum-flash process, and then turned into perovskite phase after annealing. The films had strong absorption in the visible region, and the absorption edges were about 750 nm. The optical absorption edge (Eg) values of the films with different compositions were about 1.6 eV. The PL intensity of the film with Cl-doping decreased and the peak showed a blue-shift compared to MAPbI3 film, which might be caused by the increase of the grain size and the reduction of the defect density.
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