Phase transition, optical and photoconductive properties of bay-substituted benzoporphyrin derivatives

摘要: Two benzoporphyrin derivatives substituted with long side chains at the bay positions have been synthesized through a facile route. They were confirmed to show two separate columnar phases upon cooling, i.e., hexagonal phase and rectangular phase. In particular, temperature dependence of electronic spectra revealed that Q-band split into peaks, indicating existence typical herringbone-type dimers. Moreover, their photoconductive properties studied by steady-state transient photocurrent measurements. It was found both benzoporphyrins exhibited very fast hole mobility over 0.1 cm2 V−1 s−1 in high charge carrier generation efficiency up 2%, demonstrating they are potential p-type organic semiconductors for photovoltaic devices.