Constructing D‑π‑A Type Polymers as Dopant-Free Hole Transport Materials for High-Performance CsPbI2Br Perovskite Solar Cells

Zheng Dai, Qiang Guo, Yuanjia Ding, Zhibin Wang, Naizhong Jiang, and Erjun Zhou

ACS Appl. Mater. Interfaces 2023, 15, 7, 9784–9791

Publication Date:February 9, 2023

https://doi.org/10.1021/acsami.2c23036

Efficient and stable perovskite solar cells (PSCs) rely heavily on hole-transporting materials (HTMs), with dopant-free conjugated polymers gaining interest for their high hole mobility and stability. A recent study explored the relationship between polymer structure and photovoltaic performance by using three D-π-A-type polymers with varying A units.

The energy levels, hole mobility, molecular stacking, and charge transfer were investigated for CsPbI2Br PSCs with these HTMs. The device using PE61 HTM achieved the highest power conversion efficiency at 16.72%, outperforming PBDB-T (15.13%) and J52 (15.52%), and exhibited the best long-term stability.

This demonstrates that quinoxaline is an effective A unit for D-π-A-type polymers, improving PSC photovoltaic performance.

Transient photocurrent (TPC) and transient photovoltage (TPV) were tested by a Fluxim Paios characterization system.