Anilino Derivatives of 2‐hydroxy‐1,4‐naphthoquinone as a Photosensitizer in TiO ₂ and ZnO‐Based Dye‐Sensitized Solar Cells

ABSTRACT Anilino derivatives of 2‐hydroxy‐1,4‐naphthoquinone photosensitizer, specifically 2‐hydroxy‐3‐(phenylamino)naphthalene‐1,4‐dione (LwAn), were synthesized from 1,4‐naphthoquinone and used as a light harvester in TiO 2 and ZnO‐based dye‐sensitized solar cells (DSSCs). Single‐crystal x‐ray diffraction studies confirm that LwAn crystallizes in the triclinic space group P‐1 . UV–vis spectroscopy, field‐emission scanning electron microscopy (FE‐SEM), and powder x‐ray diffraction (PXRD) were used to characterize the optical properties, morphologies, and crystallinity of the photosensitizers and photosensitized photoanodes in DSSCs. The UV–vis spectrum showed a 328 nm ( π → π *) transition in the UV region and a 459 nm ( n → π *) transition in the visible region. The PXRD pattern verifies the hexagonal wurtzite structure in ZnO photoanodes and the rutile and anatase phases in TiO 2 photoanodes. The photovoltaic and electrochemical properties of ZnO/LwAn and TiO 2 /LwAn photoelectrode‐based DSSCs were analyzed using J‐V characteristics curves and electrochemical impedance analysis. The LwAn‐sensitized TiO 2 ‐based DSSCs exhibited the highest power conversion efficiency, 0.20% (TiO 2 /LwAn), than ZnO‐based DSSCs, 0.13% (ZnO/LwAn). The reduced charge recombination at the photoanode/photosensitizer/electrolyte interface and excellent light absorption are responsible for the TiO 2 /LwAn‐based photoelectrodes' enhanced DSSCs performance. The synthesized LwAn photosensitizers effectively improve the DSSC's performance, making them promising candidates for future DSSC applications.