Heterocyclic D-A-D hole-transporting material for high-performance inverted perovskite solar cells

• Published in: Journal of materials chemistry. C, Materials for optical and electronic devices Vol. 11; no. 27; pp. 929 - 9214
• Main Authors: Tingare, Yogesh S, Su, Chaochin, Wang, Wan-Chun, Lin, Hong-Jia, Lin, Ja-Hon, Lin, Xiang-Ching, Lin, Chien-Hsiang, Huang, Tsai-Wen, Li, Wen-Ren
• Format: Journal Article
• Language: English
• Published: Cambridge Royal Society of Chemistry 13.07.2023
• Subjects: Energy conversion efficiency; Hole mobility; Material properties; Open circuit voltage; Perovskites; Photoluminescence; Photovoltaic cells; Short circuit currents; Solar cells; Space charge
• ISSN: 2050-7526; 2050-7534
• DOI: 10.1039/d3tc00710c

Small-molecule hole-transporting materials (HTMs) have gained much attention due to their structural flexibility, material properties, and stabilities, allowing for enhanced operational durability in perovskite photovoltaics. We synthesized and investigated a new class of donor-acceptor-donor (D-A-D) configured ligand type hetero-structured small molecule, WWC106 , serving as the HTM to enable high-efficiency mixed-halide lead perovskite solar cells. WWC106 is a benzimidazole-centered dopant-free HTM composed of three donors: two 4-methoxy- N -(4-methoxyphenyl)- N -phenylanilines (TPAs) and one 2-(2,2-bis(4-methoxyphenyl)vinyl)-5-methylthiophene. One of the two TPA donors is linked to the benzimidazole via a pyridine unit. Scanning electron microscopy, photoluminescence (PL) time-resolved PL, and space charge limited current measurements on WWC106 HTMs show perovskite formation with good morphology, efficient hole extraction, and hole mobility. The new D-A-D configured WWC106 -based device exhibited a high open-circuit voltage of 1.09 V and a high short circuit current density of 20.76 mA cm −2 , with the highest power conversion efficiency of 17.75%. A new hole-transporting material (HTM) based on benzimidazole-pyridine heterocyclic is synthesized for use in perovskite solar cells. The HTM has good hole transport, lower trap density, and lower electric resistance with a 17.75% efficiency.