Deposition of loosely bound organic D–A–π–A′ dyes on sensitized TiO2 film: a possible strategy to suppress charge recombination and enhance power conversion efficiency in dye-sensitized solar cells

摘要: A D–A–π–A′ dye (coded as AR-II-13) – composed of a triarylamine donor, difluorobenzothiadiazole internal acceptor and cyanoacrylic acid anchoring has been successfully synthesized via sequential C–H direct arylation, used sensitizer in dye-sensitized solar cells (DSSCs). The butoxy group at the donor side hexyl on di-substituted cyclopenta[1,2-b:5,4-b′]dithiophene (CPDT) bridge are incorporated to decrease aggregation offer physical insulation between electrolyte oxidant TiO2 films. It is demonstrated that open circuit voltage (VOC), short current (JSC) power conversion efficiency (PCE) remarkably enhanced relative conventionally fabricated cell by deposition additional sensitized impact bath solvent was observed be minimal enhancement performance exclusively ascribed loosely bound moieties providing films from I3− retarding charge recombination electrons film electrolyte, confirmed electrochemical impedance measurements. Furthermore, dipole interaction surface may play synergetic role enhancing photovoltaic resulting devices.