New pyrazine-based π-conjugated polymer for dopant-free perovskite solar cell

The polymer was engineered and synthesized for the fabrication of perovskite solar cells (PSCs). Pyrazine-based polymer is used as a hole transport material (HTM) in PSCs. Pyrazine is suitable for major transport, such as affording high hole mobility and intermolecular enhancement, and has the advantage of being inexpensive. Remarkable results are achieved by polymerizing a pyrazine-based material (PzTBr) composed of thiophene moiety with a short alkyl group on both sides and a BDT-based material (BDTEH) to yield BDTEH–PzTBr. Dopant-free processed PSCs fabricated with BDTEH–PzTBr exhibited a PCE of 13.2% for green solvent and 15.9% for chloroform solvent. Therefore, the pyrazine-based polymer is an appropriate strategy to synthesize and explore as an HTM in PSCs.

A donor–acceptor (D–A)-conjugated polymer BDTEH–PzTBr was designed and successfully used as a hole transport material in perovskite solar cells. Due to the advantage of the molecular structure, and uniform morphology, the BDTEH–PzTBr-based device achieved a good power conversion efficiency of over 15.9%. High performance is achieved using easy synthesis processes and inexpensive materials.