Chaudhary Sonu Pratap, Bhattacharyya Sayan
Department of Chemical Sciences and Centre for Advanced Functional Materials, Indian Institute of Science Education and Research (IISER) Kolkata, Mohanpur 741246, India.
ACS Appl Mater Interfaces. 2023 Nov 1;15(43):50479-50488. doi: 10.1021/acsami.3c09651. Epub 2023 Oct 20.
The performance of perovskite solar cells (PSCs) is governed by the quality of perovskite films, whereby compact, pinhole-free perovskite films are desired, in addition to its composition. We have demonstrated probe sonication as a processing technique to provide positive feedback for enhancing the perovskite film quality and photovoltaic parameters, with two systems, CHNHPbI (MAPbI) and CsFAPb(IBr). In probe sonication, the ultrasound results in the formation, growth, and collapse of the bubbles through shock wave inside the gas phase of the collapsing bubble. This phenomenon has a chemical impact on the nucleation of the perovskite phases and interconnectivity of the grains. The 60 min sonicated films with stronger hydrogen bonding network are devoid of unwanted Pb, δ-FAPbI, and PbI phases, having tightly packed homogeneous grains, minimum electron-hole recombination pathways, and improved light absorption. The surface potential remains mostly unaltered across the grains and grain boundaries, and the realignment of the Fermi energy () favors facile carrier transport. The photoconversion efficiency (PCE) of the MAPbI and CsFAPb(IBr) devices is improved by 28.1 and 17.2% in comparison to the pristine perovskites, respectively. The 60 min sonicated CsFAPb(IBr) PSC has 20.20 ± 0.40% PCE with 1000 h ambient stability having >60% retention of the original PCE.
钙钛矿太阳能电池（PSC）的性能取决于钙钛矿薄膜的质量，除了其成分外，还需要致密、无针孔的钙钛矿薄膜。我们已经证明，通过两种体系CHNHPbI（MAPbI）和CsFAPb(IBr)，探针超声处理作为一种加工技术可为提高钙钛矿薄膜质量和光伏参数提供积极反馈。在探针超声处理中，超声波通过塌缩气泡气相内的冲击波导致气泡的形成、生长和塌缩。这种现象对钙钛矿相的成核和晶粒的互连性具有化学影响。具有更强氢键网络的超声处理60分钟的薄膜不含不需要的Pb、δ-FAPbI和PbI相，具有紧密堆积的均匀晶粒、最小的电子-空穴复合路径以及改善的光吸收。整个晶粒和晶界的表面电位基本保持不变，费米能级（）的重新排列有利于载流子的轻松传输。与原始钙钛矿相比，MAPbI和CsFAPb(IBr)器件的光电转换效率（PCE）分别提高了28.1%和17.2%。超声处理60分钟的CsFAPb(IBr) PSC的PCE为20.20±0.40%，在1000小时的环境稳定性下，原始PCE的保留率>60%。
