The effects for the deposition temperature onto the structural, compositional and optical properties of pulsed laser ablated Cu2ZnSnS4 thin films grown on soda lime glass substrates

Cu2ZnSnS4 thin films were deposited on soda lime glass substrates by pulsed laser deposition at various deposition temperatures. Without experiencing the sulfurization process, the single phase Cu2ZnSnS4 thin film was deposited with no secondary phases. The grain size increased with increasing deposition temperature. The grain size at the highest temperature was approximately double than that at the lowest temperature. All Cu2ZnSnS4 thin films had a Cu-rich and S-poor state and there was a compositional change at high deposition temperature. Secondary ion mass spectrometry showed that Na ions from soda lime glass diffuse into the Cu2ZnSnS4 thin film. These Cu2ZnSnS4 thin films deposited at 300 °C exhibited good crystallinity, large particle size and ideal energy band gap (Eg = 1.52 eV), which meets the critical requirements for the thin film solar cell performance.