Key Laboratory for Physical Electronics and Devices of the Ministry of Education and Shaanxi Key Lab of Information Photonic Technique, School of Electronic and Information Engineering, Xi'an Jiaotong University, No.28, Xianning West Road, Xi'an, 710049, China.
Collaborative Innovation Center of Extreme Optics, Shanxi University, Taiyuan, 030006, China.
Adv Mater. 2017 Jun;29(23). doi: 10.1002/adma.201606964. Epub 2017 Apr 11.
Tin (Sn)-based perovskites are increasingly attractive because they offer lead-free alternatives in perovskite solar cells. However, depositing high-quality Sn-based perovskite films is still a challenge, particularly for low-temperature planar heterojunction (PHJ) devices. Here, a "multichannel interdiffusion" protocol is demonstrated by annealing stacked layers of aqueous solution deposited formamidinium iodide (FAI)/polymer layer followed with an evaporated SnI layer to create uniform FASnI films. In this protocol, tiny FAI crystals, significantly inhibited by the introduced polymer, can offer multiple interdiffusion pathways for complete reaction with SnI . What is more, water, rather than traditional aprotic organic solvents, is used to dissolve the precursors. The best-performing FASnI PHJ solar cell assembled by this protocol exhibits a power conversion efficiency (PCE) of 3.98%. In addition, a flexible FASnI -based flexible solar cell assembled on a polyethylene naphthalate-indium tin oxide flexible substrate with a PCE of 3.12% is demonstrated. This novel interdiffusion process can help to further boost the performance of lead-free Sn-based perovskites.
锡(Sn)基钙钛矿由于在钙钛矿太阳能电池中提供了无铅替代品而越来越受到关注。然而，沉积高质量的 Sn 基钙钛矿薄膜仍然是一个挑战，特别是对于低温平面异质结（PHJ）器件。在这里，通过退火堆叠的水溶液沉积甲脒碘化（FAI）/聚合物层，然后蒸发 SnI 层，展示了一种“多通道互扩散”协议，以形成均匀的 FASnI 薄膜。在该协议中，被引入的聚合物显著抑制的微小 FAI 晶体可以为与 SnI 的完全反应提供多个互扩散途径。更重要的是，使用水而不是传统的非质子有机溶剂来溶解前体。通过该协议组装的性能最佳的 FASnI PHJ 太阳能电池的功率转换效率（PCE）为 3.98%。此外，还展示了一种在聚萘二甲酸乙二醇酯-铟锡氧化物柔性基底上组装的具有 3.12% PCE 的柔性 FASnI 基柔性太阳能电池。这种新的互扩散工艺可以帮助进一步提高无铅 Sn 基钙钛矿的性能。
