Velusamy A.Tsai, Tzung-YuTzung-YuTsaiXu, Yi-XinYi-XinXuHong, Shao-HuanShao-HuanHongCHENG-LIANG LIUChiang, Chien-HungChien-HungChiangChen, Ming-ChouMing-ChouChenWu, Chun-GueyChun-GueyWu2025-09-092025-09-092025-01-0116136810https://www.scopus.com/record/display.uri?eid=2-s2.0-105013462379&origin=resultslisthttps://scholars.lib.ntu.edu.tw/handle/123456789/731957Interfacial 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 Pb2+ 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.falsediketopyrrolopyrrolePDTONperovskite solar cellsquinoidalthienoisoindigo[SDGs]SDG7journal article10.1002/smll.2025066642-s2.0-105013462379