高稳定性(EDA)(FA)2[Pb3I10]层状钙钛矿薄膜的制备与表征

为了提高钙钛矿太阳能电池在潮湿环境中的稳定性, 采用一步法, 通过在DMF中混合(EDA)I₂、(FA)I和PbI₂, 将乙二胺离子引入钙钛矿晶格, 成功制备了一种具有较高稳定性的二维片层状的钙钛矿结构薄膜。通过原位掠入射X射线衍射(GIXRD)、X射线衍射(XRD)、扫描电子显微镜(SEM)、紫外-可见吸收光谱(UV-Vis)和原子力显微镜(AFM)等方法检测分析(EDA)(FA)₂[Pb₃I₁₀]在低湿度及高湿度环境下的结构、形貌以及光学性能变化。结果表明: 制备的 (EDA)(FA)₂[Pb₃I₁₀]薄膜在相同湿度环境下比当前广泛应用于钙钛矿太阳能电池的甲胺铅碘薄膜(CH₃NH₃PbI₃)稳定性更高; 薄膜的光学带隙约为1.67 eV, 与太阳能电池最佳带隙比较接近。另外, (EDA)(FA)₂[Pb₃I₁₀]薄膜在可见光范围吸光性能较好; 薄膜的粗糙度很小, 适合制备太阳能电池, 而且, 成本较硅基太阳能电池低廉, 在分子水平较CH₃NH₃PbI₃的可调谐性更大, 使钙钛矿太阳能电池在未来大面积应用成为可能。

Fabrication and Characterization of High Stability (EDA)(FA)2[Pb3I10] Layered Perovskite Film

A new two-dimensional layered hybrid perovskite solar-cell absorber was synthesized by one-step method, using (EDA)I₂, (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.