Effects of spin speed on the properties of spin-coated Cu2ZnSnS4 thin films and solar cells based on DMSO solution

Dimethyl sulfoxide-based spin coating has demonstrated its potential for producing high quality Cu₂ZnSnS₄ (CZTS) thin films. In this work, we investigate the effects of spin speed on the properties of sulfurized CZTS thin films deposited by spin coating at three different spin speeds, 1500rpm, 2000rpm and 3000rpm. We find that the spin speed affects not only the deposition rate, but also the film morphology - the film deposited at 3000rpm shows a more densely packed and less pinhole morphology. This indicates a preference of higher spin speed for solar cell fabrications.