2-Chloro-(n-alkylamino)pyridine-1,4-naphthoquinones as photosensitizers, viz. 2-chloro-3[(pyridine-2-ylmethyl)amino]naphthalene-1,4-dione (2AMP), 2-chloro-3[(pyridine-3-ylmethyl)amino]naphthalene-1,4-dione (3AMP), and 2-chloro-3[(2-pyridine-2-ylethyl)amino)]aphthalene-1,4-dione (2AEP), are synthesized and studied for TiO2 and ZnO-based dye-sensitized solar cells (DSSCs). The FE-SEM, powder XRD, UV–Visible spectroscopy, FT-IR, and J–V characteristics were used to investigate the morphology, crystallinity, and optical and electrochemical properties of the photosensitizer-adsorbed TiO2 and ZnO photoelectrodes. 

Optical properties of photoelectrodes are noticed in the visible spectrum and are assigned to n→π* charge transfer transition. 

The PXRD pattern confirms the hexagonal Wurtzite crystal structure of ZnO and the anatase phase of TiO2 photoelectrodes. The TiO2/3AMP photoelectrode-based DSSCs exhibited higher efficiency (η) than other photoelectrodes (TiO2/2AMP, TiO2/2AEP, ZnO/2AMP, ZnO/3AMP, and ZnO/2AEP) because of its better photosensitizer adsorption and rapid electron injection.

 The photosensitizers are actively breaking down the energy barrier and reducing the electron recombination losses. The current work will provide a new method for fabricating the DSSCs that rely on D–π–A motif-based 2-Chloro-(n-alkylamino)pyridine-1,4-naphthoquinones photosensitizers and morphology-dependent photoelectrodes.