Functionalization of Donor–π–Acceptor Hole Transport Materials Enhances Crystallization and Defect Passivation in Inverted Perovskite Solar Cells: Achieving Power Conversion Efficiency >21% (Area: 1.96 cm2) and Impressive Stability
Journal
Advanced Energy and Sustainability Research
Journal Volume
4
Journal Issue
10
Date Issued
2023-10-01
Author(s)
Hung, Chieh Ming
Wu, Chi Chi
Tsao, Po Hsiung
Lung, Chia Di
Wang, Chih Hsing
Ni, I. Chih
Chu, Che Chun
Cheng, Chun Hao
Kuang, Wen Yang
Wu, Chih-I
Chen, Hsieh Chih
Abstract
Inverted perovskite solar cells (PSCs) mainly adopt polytriarylamine (PTAA) for the hole transport material (HTM), which usually brings about inferior interfacial contact owing to their hydrophobicity, high-lying highest occupied molecular orbital energy level, and deficiency of passivation groups. Herein, a series of donor–π–acceptor (D–π–A) type small molecules is demonstrated based on 2,2′:6′,2″-terpyridine (TPy) as the acceptor moiety, benzene ring as the π-linker, and incorporating various donors to act as HTMs. These TPy-based molecules coated atop PTAA manipulate the energy level and surface wettability, but the incorporation of the phenoxazine (POZ) donor can be prominent for enhancing charge transport and defect passivation, thereby simultaneously addressing the above-mentioned issues. The highest power conversion efficiency of 22.36% can be achieved with an open-circuit voltage (VOC) of 1.15 V, a short-circuit current density (JSC) of 23.96 mA cm−2, and a fill factor (FF) of 81.16% for the optimized POZ-TPy-modified device. Moreover, the power PCE of a large POZ-TPy-modified device (1.96 cm2) can still reach more than 21%. These results are among one of the highest efficiencies for inverted PSCs, indicating the enormous potential of POZ-TPy HTM in future perovskite applications.
Subjects
defect passivation | dopant-free hole-transport materials | inverted perovskite solar cells | nonradiative recombination | terpyridines
SDGs
Type
journal article