部分预成核以制备单相基于FA0.92MA0.08PbI3的高效太阳电池（英文）

Advanced partial nucleation for single-phase FA0.92MA0.08PbI3-based high-efficiency perovskite solar cells

目前为止,对于高性能钙钛矿太阳能电池(PSCs)的开发已经进行了大量的研究,并取得了显著的成果.基于FAxMA1-xPbI3的混合阳离子钙钛矿具有广泛的吸光范围和显著的热稳定性,是获得高性能器件的理想材料.然而,很难通过前驱体来控制钙钛矿膜中混合阳离子的比例.此外,高MA+含量的FAxMA1-xPbI3薄膜存在严重的相分离和大量的陷阱态,导致光伏性能较差.为了抑制相分离,本文提出了一种退火前部分成核的后处理方法,用混合的甲酰胺碘/甲铵碘(FAI/MAI)溶液处理制备的FAI-Pb I-2-DMSO中间相,最终得到的钙钛矿为FA0.92MA0.08PbI3.发现由于类似的分子结构引发了钙钛矿后处理薄膜中的离子交换,从而促进了部分成核,缺陷大大减少.因此,增加的光捕获和减少的缺陷态有助于提高开路电压和短路电流.用后处理方法制备的PSCs在大气条件下,最大PCE为20.80%, 80天后降解率为30%,具有可靠的重现性.

To date, extensive research has been carried out,with considerable success, on the development of highperformance perovskite solar cells(PSCs). Owing to its wide absorption range and remarkable thermal stability, the mixedcation perovskite FAxMA1-xPbI3(formamidinium/methylammonium lead iodide) promises high performance. However, the ratio of the mixed cations in the perovskite film has proved difficult to control with precursor solution. In addition, the FAxMA1-xPbI3 films contain a high percentage of MA+and suffer from serious phase separation and high trap states, resulting in inferior photovoltaic performance. In this study, to suppress phase separation, a post-processing method was developed to partially nucleate before annealing, by treating the as-prepared intermediate phase FAI-Pb I2-DMSO(DMSO: dimethylsulfoxide) with mixed FAI/MAI solution. It was found that in the final perovskite, FA0.92MA0.08 PbI3, defects were substantially reduced because the analogous molecular structure initiated ion exchange in the post-processed thin perovskite films, which advanced partial nucleation. As a result, the increased light harvesting and reduced trap states contributed to the enhancement of open-circuit voltage and short-circuit current. The PSCs produced by the post-processing method presented reliable reproducibility, with a maximum power conversion efficiency of 20.80% and a degradation of ~30% for 80 days in standard atmospheric conditions.