Nanocrystalline MoO₃/Polymerized Dibromo‐EDOT as Hybrid Nanocomposite: Efficient Hole Transport Material for Solid‐State Dye‐Sensitized Solar Cells

Abstract A hybrid inorganic−polymer hole‐transport material (HTM) exhibited good photovoltaic properties owing to the excellent combination of desirable characteristics of the organic and inorganic materials. Solution‐processed nanocrystalline MoO₃ and conducting polymerized dibromo‐3,4‐ethylenedioxythiophene (EDOT) were mixed to develop a hybrid material, which was used in efficient solid‐state dye‐sensitized solar cells (ssDSSCs) as an HTM. Nanocrystalline MoO₃ was prepared by a low‐temperature solution method, and the dibromo‐EDOT was prepared from commercially available EDOT by a conventional bromination method. The incorporation of MoO₃ into a hybrid HTM significantly improved the device efficiency owing to its high charge transport mechanism and suppression of the recombination in the ssDSSCs. Furthermore, we examined the influence of the blend ratio of MoO₃ and dibromo‐EDOT on the photovoltaic performance of the devices. Moreover, the ssDSSCs were characterized by electrochemical impedance spectroscopy and Tafel polarization analysis to examine the charge transfer kinetics. The improved performance of the ssDSSCs could be attributed to increased charge carrier collection by the hybrid HTM. The photovoltaic results revealed that the device fabricated with a hybrid HTM containing 0.2 wt% MoO₃ showed the best efficiency_.