Synthesis and photovoltaic performance of dihydrodibenzoazepine-based sensitizers with additional lateral anchor

Three novel metal-free organic dyes with dihydro-5 H -dibenzo[ b , f ]azepine as a donor and cyanoacrylic acid as an anchoring unit were designed as an innovative linear skeleton of D–D–π–A type of organic dyes. The conversion efficiency of the derived dye-sensitized solar cells is moderate. Among them, the dye with a hydroxy group as an additional anchoring moiety exhibited the highest UV–Vis absorption with a maximum molar extinction coefficient of 24,136 M −1  cm −1 at λ max  = 458 nm and the best photovoltaic performance with an overall power conversion efficiency of 4.88%, while the dye with a carboxy group as an additional anchoring moiety exhibited the lowest conversion efficiency (4.52%). The results show that the dye loading on the film and photovoltaic performance of the dyes were influenced by the additional anchoring units.