Two quinoidal-type ThBF derivatives incorporating triphenylamine moieties, namely ThBF-TPA and ThBF-OMeTPA, were designed as perovskite/hole transport layer (HTL) interface engineering materials for perovskite solar cells (PSCs). They were demonstrated to effectively passivate perovskite surface defects and reduce the non-radiative recombination through coordination with Pb²⁺ on the perovskite surface. Consequently, PSCs incorporating ThBF-OMeTPA fabricated under ambient conditions achieved a high PCE of 19.09% with substantial enhancement in stability.