Passivation of Inverted Perovskite Solar Cells by Trifluoromethyl-Group-Modified Triphenylamine Dibenzofulvene Hole Transporting Interfacial Layers
Nurlailatush Sholihah, Han-Ching Cheng, Jhong-Ci Wang, Jen‐Shyang Ni, Yang‐Yen Yu, Chih‐Ping Chen, Yung‐Chung Chen
Abstract
In this work, we synthesized trifluoromethyl group series modified triphenylamine dibenzofulvenes, named as CC-1–3, as a hole transporting interfacial layer to obtain well-matched energy levels and long-term stability features in NiO x -based inverted perovskite solar cells. The optical and thermal properties of these new compounds were investigated. All the compounds were combined with NiO x and formed layer by layer as hole transporting layers (HTLs). The morphology, energy level, and charge transfer resistance were all compared. The NiO x / CC-3 bilayer-based architecture improved the energy level alignment, film morphology, crystallinity, and hole transportation, allowing for a high-quality perovskite layer and interfacial contact behavior. As a result, this inverted cell significantly improved open-circuit voltage ( V OC ), short current density ( J SC ), fill factor (FF), and power conversion efficiency (PCE) values up to 21.66 mA cm –2, 1.105 V, 79.33%, and 19.82%, respectively. Remarkably, the NiO x / CC-3 device had negligible hysteresis and long-term stability, retaining over 90% of its original efficiencies under argon and over 80% in the ambient atmosphere after 40 days. This paper shows a new chemical design, particularly for the trifluoromethyl group effect, and a complete understanding of the bilayer HTL technique and its promise for producing efficient cell performance.