Molecular engineering of metal-free organic sensitizers with polycyclic benzenoid hydrocarbon donor for DSSC applications: The effect of the conjugate mode

摘要: Abstract Optimizing the molecular structure to adjust properties of photosensitizer is one crucial means improve power conversion efficiency dye-sensitized solar cells (DSSCs). In this paper, four aromatic fused rings were selected as electron donor units construct photosensitizers PBT–series. The effects structural differences in moiety on photophysical and photochemical molecules investigated detail. results show that devices based dyes with triphenylene or fluoranthene can yield higher short-circuit photocurrent densities (Jsc) open-circuit voltages (Voc) than reference pyrene phenanthrene donor, (PCE) increased by 37% 23%, respectively. PBT–2 PBT–4 sensitizers have better light absorption due stronger intramolecular charge transfer (ICT) transitions, which helps increase devices, while they also exhibit significantly lower recombination rates. Eventually, PBT–2-based showed best 7.67% under standard global AM 1.5 conditions.