A nanocomposite p-type semiconductor film for possible application in solar cells: Photo-electrochemical studies

• A facile electrochemical route for preparation of composite solar energy materials.
• Photoelectrochemical response of a p-type nanocomposite semiconductor film.
• Liquid junction photonic phenomena from basic viewpoints.

Semiconductor films play a crucial role when it comes to modern solar-based technologies to generate electricity, produce solar fuels, or convert the environmental pollutants to other harmless materials. In this paper, using an interesting simple as well as versatile electrochemical route, a nanocomposite Cu/Zn/Sn oxide semiconductor film was fabricated on a fluorine doped tin oxide glass and investigated as a photocathode of quantum dot solar cells in a sulfide/polysulfide electrolyte solution. X-ray diffraction analyses revealed a composite nature for this electrodeposited film. A broadband light absorption was witnessed and the band gap (1.63 eV) was determined through Tauc׳s procedure. Scanning electron micrographs exhibited a non-smooth morphology for this composite film, which provides a greater area for heterogeneous reactions occurring upon the electrode surface. Mott–Schottky and potentiodynamic polarization plots indicated that the fabricated electrode acts as a complex p-type photocathode. The electrochemical impedance studies proved that under light irradiation, by photo-generation of charge carriers (electron-hole), the interfacial charge transfer resistance decreases and the cathodic current becomes consequently enhanced. After coating (photodeposition) with silver, a complicated photoelectrochemical response was finally observed and the findings were explained in detail.