Chen, C.-H.C.-H.ChenTing, H.-C.H.-C.TingLi, Y.-Z.Y.-Z.LiLo, Y.-C.Y.-C.LoSher, P.-H.P.-H.SherWang, J.-K.J.-K.WangChiu, T.-L.T.-L.ChiuLin, C.-F.C.-F.LinHsu, I.-S.I.-S.HsuLee, J.-H.J.-H.LeeLiu, S.-W.S.-W.LiuJIUN-HAW LEE2019-07-312019-07-312019https://www.scopus.com/inward/record.uri?eid=2-s2.0-85062374953&doi=10.1021%2facsami.8b20415&partnerID=40&md5=4cce90761000688cfefe91acfdc1bdeehttps://scholars.lib.ntu.edu.tw/handle/123456789/415806Four new donor-acceptor-acceptor (D-A-A) type molecules (DTCPB, DTCTB, DTCPBO, and DTCTBO), wherein benzothiadiazole or benzoxadiazole serves as the central A bridging triarylamine (D) and cyano group (terminal A), have been synthesized and characterized. The intramolecular charge-transfer character renders these molecules with strong visible light absorption and forms antiparallel dimeric crystal packing with evident Ï-Ïintermolecular interactions. The characteristics of the vacuum-processed photovoltaic device with a bulk heterojunction active layer employing these molecules as electronic donors combining C 70 as electronic acceptor were examined and a clear structure-property-performance relationship was concluded. Among them, the DTCPB-based device delivers the best power conversion efficiency (PCE) up to 6.55% under AM 1.5 G irradiation. The study of PCE dependence on the light intensity indicates the DTCPB-based device exhibits superior exciton dissociation and less propensity of geminated recombination, which was further verified by a steady photoluminescence study. The DTCPB-based device was further optimized to give an improved PCE up to 6.96% with relatively high stability under AM 1.5 G continuous light-soaking for 150 h. This device can also perform a PCE close to 16% under a TLD-840 fluorescent lamp (800 lux), indicating its promising prospect for indoor photovoltaic application. © 2019 American Chemical Society.[SDGs]SDG7Charge transfer; Efficiency; Heterojunctions; Light absorption; Molecules; Synthesis (chemical); Ambient light; Device stability; Organic photovoltaics; Small molecules; Vacuum process; DAA configuration; Lightjournal article10.1021/acsami.8b204152-s2.0-85062374953