A Novel Ethanol-Based Non-Particulate Ink for Spin-Coating Cu2ZnSnS4 Thin Film

Abstract

The Cu2ZnSnS4 (CZTS) thin films were fabricated by the direct solution coating method using a novel non-particulate ink. The ink was formulated using ethanol as the solvent and 1,2-diaminopropane as the complex-ing agent. The pure phase kesterite films with good crystallinity, large-sized crystals and excellent electrical properties were prepared by the spin-coating deposition technique using the homogeneous and air-stable ink. It was found that the subsequent pre-treatment temperature had an influence on the film crystallinity and electrical properties. The best film was obtained by pre-treating the spin-coated film at 250 °C, and then post-annealing at 560 °C. The film shows a narrow bandgap of 1.52 eV and excellent electrical properties, with a resistivity of 0.07 Ocm, carrier concentration of 3.0 x 1017 cm-3, and mobility of 4.15 cm2 V-1 s-1. The novel non-particulate ink is promising for printing high quality CZTS thin films as absorber layers of thin film solar cells.