State Key Laboratory of Electronic Thin Films and Integrated Devices, and School of Optoelectronic Information, University of Electronic Science and Technology of China (UESTC), Chengdu, Sichuan 610054, China.
Department of Electrical & Computer Engineering, and Center for Nanoscale Science & Engineering, University of Kentucky, Lexington, Kentucky 40506, USA.
Nanoscale. 2016 Dec 1;8(47):19654-19661. doi: 10.1039/c6nr07076k.
While most work carried out to date has focused on the solvent annealing of perovskite, in the present work, we focused on the solvent annealing of lead iodide. Based on the two-step spin-coating method, we designed a screening method to search for an effective solvent annealing process for PbI. PbI films were annealed in diverse solvent atmospheres, including DMF, DMSO, acetone, and isopropanol (IPA). We found that the solvent annealing of PbI in the DMF, acetone, and IPA atmospheres resulted in dense PbI films, which impeded the complete conversion of PbI to CHNHPbI. Surprisingly, employing the DMSO solvent annealing process for PbI led to porous PbI, which facilitated the complete conversion of PbI to perovskite with larger grain sizes. Solar cells fabricated using the DMSO solvent annealing process exhibited the best efficiency of 18.5%, with a fill factor of 76.5%. This unique solvent annealing method presents a new way of controlling the perovskite film quality for highly efficient solar cells.
虽然迄今为止大多数工作都集中在钙钛矿的溶剂退火上，但在本工作中，我们专注于碘化铅的溶剂退火。基于两步旋涂法，我们设计了一种筛选方法来寻找有效的 PbI 溶剂退火工艺。PbI 薄膜在包括 DMF、DMSO、丙酮和异丙醇（IPA）在内的多种溶剂气氛中进行退火。我们发现，DMF、丙酮和 IPA 气氛中的 PbI 溶剂退火导致 PbI 薄膜致密，这阻碍了 PbI 向 CHNHPbI 的完全转化。令人惊讶的是，采用 DMSO 溶剂退火工艺处理 PbI 会导致 PbI 多孔化，这有利于 PbI 完全转化为具有更大晶粒尺寸的钙钛矿。采用 DMSO 溶剂退火工艺制备的太阳能电池表现出最佳的 18.5%效率，填充因子为 76.5%。这种独特的溶剂退火方法为高效太阳能电池提供了一种控制钙钛矿薄膜质量的新途径。
