Research of decomposition mechanism of mixed cation-anionic metal halide perovskite material

于2022财政年度，该研究员参与多个研究项目，并指导两名博士生。特别是，她参与了三个项目：第一个项目侧重于使用苯乙基卤化铵分子对钙钛矿层进行钝化，旨在了解这些分子在钙钛矿表面上的作用机制，特别是考虑到不同的钙钛矿成分和不同卤化物（碘，溴和氯）的影响。事实上，在文献中众所周知，这些钝化分子改善稳定性和器件性能，但在化学机制上没有一致的协议。第二个项目的重点是为常用的自组装分子（2PACz）开发新的沉积方法，该分子用作p-i-n器件配置中的空穴传输材料。这通常是旋涂的，并且这种沉积方法已经显示出在制造高性能器件方面是有效的，但是不允许在大面积器件上均匀覆盖。因此，我们表明，可以采用替代的沉积方法，如热蒸发和喷涂技术，后者是特别有效的高，甚至更高的设备性能相比，传统的旋涂方法。该研究员还试图制造大面积器件（面积22.4cm 2），但由于难以在大面积上沉积器件的一部分，控制器件的性能仍然很低。第三个项目处于早期阶段，涉及用作自组装分子的新电子传输分子。

In FY2022 the fellow worked on several research projects and supervised two PhD students. In particular, she worked on three projects: the first focuses on the passivation of the perovskite layer using phenethyl ammonium-halide molecules with the aim to understand the mechanism of these molecules on the perovskite surface, specifically taking into account different perovskite compositions and the effect of different halides (iodine, bromine and chlorine). It is in fact well known in literature that these passivation molecules improve both stability and device performance, but there is no unanimous agreement on the chemical mechanism. The second project focuses on developing new deposition methods for the commonly used self-assembly molecule (2PACz), used as hole transporting material in p-i-n device configuration. This is usually spin-coated and this deposition methos has shown to be effective in making high performing devices but does not allow a uniform coverage on large area devices. We therefore show that alternative deposition methods can be employed, such as thermal evaporation and spray-coating techniques, with the latter being particularly effective for high or even higher device performances compared to the traditional spin-coating method. The fellow also tried to fabricate large area devices (area 22.4cm2) but the performances of control devices remain low due to difficulties in depositing part of the device on large area. The third project is at early stages and involves new electron transporting molecules to be used as self-assembly molecules.