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.