Mechanochemically synthesized ternary chalcogenide CuInSe2/TiO2 nanocomposite for solar cell applications

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Abstract

In this paper, the simple mechanochemical synthesis of CuInSe₂/TiO₂ nanocomposite is described. CuInSe₂/TiO₂ nanocomposite was characterized from the crystal structure, microstructural, morphology, surface, optical, and optoelectrical properties viewpoints. X-ray diffraction has confirmed the nanocrystalline character of all components of the nanocomposite, the crystallite size for CuInSe₂ (18 nm) being larger than in the case of both TiO₂ phases (5 and 8 nm for rutile and anatase, respectively). Raman spectroscopy confirmed the presence of both components in the synthesized nanocomposite. SEM has shown that the nanoparticles are agglomerated into larger grains. High-resolution XPS analysis confirmed the presence of all elements with their expected oxidation states. The measured optical properties using UV-Vis spectroscopy exhibit stronger absorption from the ultraviolet to visible region with the determined optical bandgap 1.3 eV for mechanochemically synthesized CuInSe₂/TiO₂ nanocomposite. The photocurrent increased by 57% in CuInSe₂/TiO₂ nanocomposite compared to CuInSe₂ under illumination in comparison with that in the dark state.