Department of Materials Science & Metallurgy , University of Cambridge , 27 Charles Babbage Road , Cambridge CB3 0FS , U.K.
Photovoltaics Department , imec, Thin Film PV Group , Kapeldreef 75 , 3001 Leuven , Belgium.
ACS Appl Mater Interfaces. 2019 Dec 11;11(49):45646-45655. doi: 10.1021/acsami.9b15520. Epub 2019 Dec 2.
Hybrid metal halide perovskites have emerged as a potential photovoltaic material for low-cost thin film solar cells due to their excellent optoelectronic properties. However, high efficiencies obtained with lab-scale cells are difficult to replicate in large modules. The upscaling process requires careful optimization of multiple steps, such as laser scribing, which divides a module into serially connected cells using a pulsed laser beam. In this work, we characterize the effect of laser scribing on the perovskite layer adjacent to a P3 scribe line using analytical scanning and cross-sectional transmission electron microscopy techniques. We demonstrate that lateral flow of residual thermal energy from picosecond laser pulses decomposes the perovskite layer over extended length scales. We propose that the exact nature of the change in perovskite composition is determined by the presence of preexisting PbI grains and hence by the original perovskite formation reaction. Furthermore, we show that along the P3 lines, the indium tin oxide contact is also damaged by high-fluence pulses. Our results provide a deeper understanding on the interaction between laser pulses and perovskite solar modules, highlighting the need to minimize material damage by careful tuning of both laser parameters and the device fabrication procedure.
混合卤化金属钙钛矿因其优异的光电性能而成为低成本薄膜太阳能电池的潜在光伏材料。然而，在实验室规模的电池中获得的高效率难以在大型模块中复制。扩大规模的过程需要仔细优化多个步骤，例如激光划线，它使用脉冲激光束将模块划分为串联连接的电池。在这项工作中，我们使用分析扫描和横截面透射电子显微镜技术来表征激光划线对紧邻 P3 划线的钙钛矿层的影响。我们证明，来自皮秒激光脉冲的残余热能的横向流动会在扩展的长度尺度上分解钙钛矿层。我们提出，钙钛矿成分变化的确切性质取决于预先存在的 PbI 晶粒的存在，因此取决于原始钙钛矿形成反应。此外，我们表明，沿着 P3 线，铟锡氧化物接触也会受到高能量脉冲的损坏。我们的结果提供了对激光脉冲与钙钛矿太阳能模块相互作用的更深入了解，突出了需要通过仔细调整激光参数和器件制造工艺来最小化材料损伤的必要性。
