Work

Synergistic Interface Engineering with Quinoidal Thienoisoindigo and PDTON Achieves 23.7% Efficiency in Perovskite Solar Cells

Year: 2025

Type: article

Abstract: Interfacial defects between the perovskite absorber and hole transport layer (HTL) remain a major bottleneck in the performance and stability of perovskite solar cells (PSCs). A synergistic interface engineering strategy is introduced, combining quinoidal small molecules—thienoisoindigo ( TIIQ ) and diketopyrrolopyrrole ( DPPQ )—in the perovskite precursor solution, with the amphiphilic polymer PDTON incorporated via the antisolvent. This dual‐functional approach significantly improves perovskite film quality by promoting larger grain growth, reducing trap densities, and enhancing charge transport. Fourier‐transform infrared spectroscopy reveals a redshift in the cyano group absorption bands, confirming coordination between TIIQ / DPPQ and undercoordinated Pb 2+ ions, enabling effective defect passivation. Among all configurations, the TIIQ–PDTON‐treated film ( T‐PSK@PD ) exhibits the highest crystallinity, smoothest morphology, and lowest recombination loss, delivering a champion power conversion efficiency (PCE) of 23.71% with 95% efficiency retention after 1920 h under ambient conditions. This study also marks the first successful application of high‐performance n‐type organic field‐effect transistor materials as functional additives in lead‐based PSCs. The multifunctional additive strategy offers a promising platform for addressing interfacial limitations, paving the way toward efficient and stable perovskite photovoltaics.

Source: Small

DOI: 10.1002/smll.202506664