Quaternary Cu2NiSnS4 thin films as a solar material prepared through electrodeposition

•This letter fabricated the CNTS thin films by an electrodeposition technique.•Synthesis and understanding of the fundamental properties of CNTS are investigated.•CNTS showed the high absorption coefficient and a suitable optimal band gap.•The CNTS/CdS heterojunction was coherent that was important for thin-film PVs.•The valences of the constituents of CNTS thin film were Cu+1, Ni+2, Sn+4 and S−2.

Quaternary chalcopyrite compounds (Cu2XSnS4, X=Zn, Fe, Co, Ni) are promising candidate materials for thin-film solar cells because of their abundance and nontoxic compositions. Here, 1.2-μm-thick Cu2NiSnS4 (CNTS) thin films were successfully fabricated through electrodeposition. The structural, morphological, and optical properties of the CNTS thin films were characterized through high-resolution X-ray diffraction, field emission scanning electron microscopy, and ultraviolet–visible–near-infrared spectrophotometry. The bonding properties of CNTS was measured through Raman scattering, which revealed two principal Raman peaks of A1 mode at approximately 280 and 350 cm−1. The morphology of CNTS was uniform with an average grain size of 1±0.2 μm. The valences of the thin-film constituents were Cu+1, Ni+2, Sn+4, and S−2. The optical band gap of CNTS was approximately 1.2 eV, which is suitable for thin-film photovoltaic applications.