In situ growth of Cu2ZnSnS4 thin films by reactive magnetron co-sputtering

High-quality Cu2ZnSnS4 (CZTS) thin films were first in situ grown by a reactive magnetron co-sputtering technique. Raman examination and XRD analysis indicate that the grown film shows a single CZTS phase with good crystallinity and strong preferential orientation along (1 1 2) plane. SEM analysis reveals a homogeneous, compact surface morphology and large columnar grains throughout thickness for the film. The in situ grown CZTS film demonstrates an optical absorption coefficient of higher than 104 cm−1 and an optical band gap of 1.52±0.01 eV. The carrier concentration, resistivity and mobility of the CZTS film are 3.9×1016 cm−3, 5.4 Ω cm and 30 cm2 V−1 s−1, respectively and the conduction type is p-type. These optical and electrical properties are suitable for a thin film solar cell fabrication.