2022年12月8日，澳大利亚新南威尔士大学Martin Green和郝晓静教授团队在《自然—光子学》杂志发表论文，研究发现了基于烷基硫醇添加剂稳定的spiro-OMeTAD来助力钙钛矿太阳能电池。
在这里，研究人员报告了一种简便的方法，基于在spiro-ometad HTM中加入低成本的烷基硫醇添加剂(1-十二烷基硫醇，DDT)。研究团队发现DDT提供了一个更有效和可控的掺杂过程，显著减少了掺杂时间，使HTM在空气活化前达到相当的性能。DDT和LiTFSI的协同作用提高了HTM体中掺杂剂的浓度，减少了它们在界面上的积累，增强了HTM在润湿、热和光应力下的结构完整性。研究人员利用DDT处理过的spiro-ometad作为HTM制备了钙钛矿太阳能电池。他们最好的设备的认证功率转换效率为23.1%。
此外，该器件在1,000h的连续照明下可保持90%的峰值性能。他们的发现代表着在生产掺杂spiro-ometad，以及其可靠的应用和未来的设备商业化方面向前迈出的重要的一步。
据了解，Spiro-OMeTAD是光电子器件中最广泛应用的空穴传输材料(HTMs)之一，通常需要与锂化合物(LiTFSI)进行化学掺杂才能获得足够的导电性和高效的空穴提取。然而，掺杂步骤需要一个活化过程，该过程包括将所述混合薄膜暴露于环境气氛中。此外，锂掺杂剂诱导结晶，其吸湿性对器件性能和寿命产生负面影响。
附：英文原文
Title: Perovskite solar cells based on spiro-OMeTAD stabilized with an alkylthiol additive
Author: Liu, Xu, Zheng, Bolin, Shi, Lei, Zhou, Shujie, Xu, Jiangtao, Liu, Ziheng, Yun, Jae Sung, Choi, Eunyoung, Zhang, Meng, Lv, Yinhua, Zhang, Wen-Hua, Huang, Jialiang, Li, Caixia, Sun, Kaiwen, Seidel, Jan, He, Mingrui, Peng, Jun, Hao, Xiaojing, Green, Martin
Issue&Volume: 2022-12-08
Abstract: Spiro-OMeTAD, one of the most widely used hole-transport materials (HTMs) in optoelectronic devices, typically requires chemical doping with a lithium compound (LiTFSI) to attain sufficient conductivity and efficient hole extraction. However, the doping step requires an activation process that comprises exposure of the blend films to an ambient atmosphere. Additionally, the lithium dopant induces crystallization, and its hygroscopic nature negatively impacts device performance and lifetime. Here we report a facile approach based on the incorporation of a low-cost alkylthiol additive (1-dodecanethiol, DDT) in the spiro-OMeTAD HTM. We discover that DDT provides a more efficient and controllable doping process with significantly reduced doping duration, enabling the HTM to achieve comparable performance before air activation. The coordination between DDT and LiTFSI increases the concentration of dopants in the HTM bulk, reduces their accumulation at interfaces, and enhances the structural integrity of the HTM under wetting, heat and light stress. We fabricate perovskite solar cells using DDT-treated spiro-OMeTAD as the HTM. Our best devices exhibit a certified power conversion efficiency of 23.1%. Furthermore, the devices can retain 90% of peak performance under continuous illumination for 1,000h. Our findings represent an important step forward in the production of doped spiro-OMeTAD, as well as its reliable application and future device commercialization.
DOI: 10.1038/s41566-022-01111-x
Source: https://www.nature.com/articles/s41566-022-01111-x