Management of Donor and Acceptor Building Blocks in Dopant‐Free Polymer Hole Transport Materials for High‐Performance Perovskite Solar Cells. (30th August 2022)

• Record Type: Journal Article
• Authors: Fu, Qiang; Liu, Hang; Li, Shitong; Zhou, Tong; Chen, Mingqian; Yang, Yang; Wang, Jian; Wang, Rui; Chen, Yongsheng; Liu, Yongsheng
• Is Part Of: Angewandte Chemie. Volume 134:Number 43(2022)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2022-08-30
• Subjects: Defect Passivation -- Dopant-Free -- Hole Transport Materials -- Perovskite Solar Cells -- Polymer; Chemistry -- Periodicals; 540
• DOI: 10.1002/ange.202210356
• Languages: English
• ISSNs: 0044-8249

Abstract

Abstract: The dominant hole transport material (HTM) in state‐of‐the‐art perovskite solar cells (PSCs) is Spiro‐OMeTAD, which needs to be doped using hydrophilic dopants to improve its hole mobility and conductivity, resulting in inferior device stability. Here, we propose an effective molecular design strategy to construct dopant‐free polymer HTMs by selecting four structurally related polymers and investigating their structure–property relationship. It is found that the donor and acceptor units with longitudinal conjugate extension, such as BDT‐T and BDD, could not only enhance the planarity of the conjugated polymer backbone and tune the energy levels but also promote the face‐on orientation, resulting in superior charge extraction and transport. The optimized device utilizing dopant‐free polymer HTM shows a high open‐circuit voltage of 1.19 V and a champion efficiency of 24.04 % with greatly improved operational stability, making it among the best performance PSCs based on dopant‐free HTMs. Abstract : A polymer design strategy was proposed by managing the donor and acceptor building blocks with longitudinal extended conjugation for dopant‐free hole transport materials (HTMs). The optimized device based on the polymer HTM constructed by longitudinal extended BDT‐T and BDD units shows a champion power conversion efficiency of 24.04 % and greatly improved operational stability.