Branched Fluorenylidene Derivatives with Low Ionization Potentials as Hole-Transporting Materials for Perovskite Solar Cells

Aistė Jegorovė; Jianxing Xia; Matas Steponaitis; Maryte Daskeviciene; Vygintas Jankauskas; Alytis Gruodis; Egidijus Kamarauskas; Tadas Malinauskas; Kasparas Rakstys; Khalid A Alamry; Vytautas Getautis; Mohammad Khaja Nazeeruddin

doi:10.1021/acs.chemmater.3c00708

Branched Fluorenylidene Derivatives with Low Ionization Potentials as Hole-Transporting Materials for Perovskite Solar Cells

Chem Mater. 2023 Jul 29;35(15):5914-5923. doi: 10.1021/acs.chemmater.3c00708. eCollection 2023 Aug 8.

Affiliations

¹ Department of Organic Chemistry, Kaunas University of Technology, Radvilenu pl. 19, Kaunas, 50254 Lithuania.
² Institute of Chemical Sciences and Engineering, École Polytechnique Federale de Lausanne (EPFL), Lausanne, 1015 Switzerland.
³ Institute of Chemical Physics, Vilnius University, Sauletekio al. 3, Vilnius, 10257 Lithuania.
⁴ Chemistry Department, Faculty of Science, King Abdulaziz University, P.O. Box 80203, 21589 Jeddah, Saudi Arabia.

Abstract

A group of small-molecule hole-transporting materials (HTMs) that are based on fluorenylidene fragments were synthesized and tested in perovskite solar cells (PSCs). The investigated compounds were synthesized by a facile two-step synthesis, and their properties were measured using thermoanalytical, optoelectronic, and photovoltaic methods. The champion PSC device that was doped with lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) reached a power conversion efficiency of 22.83%. The longevity of the PSC device with the best performing HTM, V1387, was evaluated in different conditions and compared to that of 2,2',7,7'-tetrakis(N,N-di-p-methoxyphenylamine)-9,9'-spirobifluorene (spiro-MeOTAD), showing improved stability. This work provides an alternative HTM strategy for fabricating efficient and stable PSCs.