Carbazole-Based Bolaamphiphiles with Complex Self-Assembly for Perovskite Solar Cells Application

Carbazole-based bolaamphiphiles, featuring two thiophenes interconnected by a central carbazole as rigid core, decorated with three lateral chains and two sticky glycerol end groups, can exhibit complex self-assembly structures of square honeycomb via smectic A to body-centered cubic mesophase in bulk state and multiplex supramolecular organogels in solvent through alkyl chain engineering. The relevant self-assembly mechanism has been elucidated based on polarizing optical microscopy, differential scanning calorimetry, X-ray diffraction, and scanning electron microscopy measurements, as well as theoretical calculations. It is very interesting and fascinating to find that such carbazole-based bolaamphiphiles can be integrated into the Spiro hole transport layer of perovskite solar cells, enhancing the photoelectric conversion efficiency to 23.39%.