Fabrication and Characterization of High Stability (EDA)(FA)$lt;inf$gt;2$lt;/inf$gt;[Pb$lt;inf$gt;3$lt;/inf$gt;I$lt;inf$gt;10$lt;/inf$gt;] Layered Perovskite Film

Abstract

A new two-dimensional layered hybrid perovskite solar-cell absorber was synthesized by one-step method, using (EDA)I-2, (FA)I, and PbI2 with a 1 : 2 : 3 stoichiometric ratio in a solvent mixture of N, N-dimethylformamide(DMF). Ethylenediamine(EDA) cation was introduced into the perovskite lattice to synthesize a layered structure with improved resistance to the degradation by humidity in air. The effects of humidity and time on crystal structure, composition, morphology, and absorption spectra of (EDA)(FA)(2)[Pb3I10] and CH3NH3PbI3 were analyzed by in situ grazing incidence X-ray diffraction(GIXRD), X-ray diffraction (XRD), scanning electron microscope (SEM), atomic force microscope(AFM), and UV-Vis spectroscope. The results reveal that the prepared (EDA)(FA)(2)[Pb3I10] film is more moisture resistant than the CH3NH3PbI3 film which is widely used in the perovskite solar cell. SEM analysis reveals that the (EDA)(FA)(2)[Pb3I10] film has a layered structure, which can reduce the degradation caused by moisture. What's more, UV-Vis light absorption spectroscopy and atomic force microscopy(AFM) results show that the layered structure film is also a suitable absorber for perovskite solar cells. Photoluminescence spectrum(PL) reveals that bandgap of the (EDA)(FA)(2)[Pb3I10] film is 1.67 eV, which is close to the optimum value for solar photoelectric conversion. As compared to CH3NH3PbI3 film, the low-cost perovskite structure offers greater tunability on a molecular level for further material optimization and possibility for widely used in the future.