All-Inorganic CsPbBr3 Perovskite Films Prepared by Single Source Thermal Ablation
All-Inorganic CsPbBr3 Perovskite Films Prepared by Single Source Thermal Ablation
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DOI：
10.3389/fchem.2020.00313
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发表时间：
2020-04-21
影响因子：
5.5
通讯作者：
Mosca, Roberto
中科院分区：
文献类型：
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作者：
Nasi, Lucia;Calestani, Davide;Mosca, Roberto
混合有机卤化铅钙钛矿正成为下一代光电子学的基准材料，并在其他应用中发挥非常重要的作用，如光电探测器和发光二极管。然而，阻碍这些材料大规模应用的最重要的问题仍然是由于有机阳离子导致的固有不稳定性。尽管用无机铯（Cs）取代增强了稳定性，但在大多数情况下，完全无机钙钛矿的溶液沉积方法导致高表面粗糙度和差的表面覆盖。这项工作报告的蒸发的CsPbBr 3前体的单源热烧蚀，显示刚刚沉积后的膜组成的混合物的CsPbBr 3，CsPb2Br 5，和Cs4PbBr 6由于垂直的组成梯度。我们指出，由于CsPbBr3具有较高的热力学稳定性，温和的沉积后处理导致CsPb2Br5和Cs4PbBr6转化为CsPbBr3。转化结果为光滑和无针孔的CsPbBr 3膜具有良好的光吸收和发射性能。我们证明了所获得的薄膜的平面器件的适用性，通过制备基于钙钛矿的纯绿色发光二极管，从而促进单源热烧蚀作为一种有前途的替代沉积技术的所有无机钙钛矿为基础的设备。
Hybrid organo-lead halide perovskites are becoming the benchmark material for next generation photovoltaics and a very important player for other applications such as photodetectors and light emitting diodes. Nevertheless, the most important issue hindering the large-scale application of these materials remains their intrinsic instability due to the organic cation. Although the substitution with inorganic cesium (Cs) enhances stability, in most cases solution deposition methods of fully inorganic perovskites result in high surface roughness and poor surface coverage. This work reports on the evaporation of the CsPbBr3 precursor by Single Source Thermal Ablation, showing that just after deposition films consist of a mixture of CsPbBr3, CsPb2Br5, and Cs4PbBr6 due to a vertical composition gradient. We point out that mild post deposition treatments lead to the conversion of CsPb2Br5 and Cs4PbBr6 into CsPbBr3 due to its higher thermodynamic stability. Conversion results into smooth and pinhole-free CsPbBr3 films with good light absorption and emission properties. We demonstrate the suitability of obtained films for planar devices by preparing perovskite-based pure-green light emitting diodes, thus promoting Single Source Thermal Ablation as a promising alternative deposition technique for all-inorganic perovskite-based devices.