Characterisation and properties of Cu₂ZnSnS₄ thin films synthesised by sputtering from an alloy target

Abstract

Cu 2 ZnSnS 4 (CZTS) thin films were synthesised on glass substrates by sulphurising sputtered metallic precursors in H 2 S + N 2 atmosphere at 500 °C. The influences of the radio frequency (RF) sputtering power on the structure, surface morphology, optical and electrical properties of the thin films were investigated. Scanning electron microscopy, X-ray diffraction, Raman and UV-vis NIR spectroscopy were used to characterise the films. All the CZTS thin films exhibited a dominant kesterite structure. With increasing sputtering power, secondary phases in the films reduced, and the surface became more compact. The optimum quality films with poor-Cu and rich-Zn were obtained when the sputtering power was 90 W, and the optical band gap, carrier concentration, resistivity and mobility were 1.47 eV, 2.07 × 10 18 cm −3 , 2.37 Ω cm and 1.38 cm 2 s −1 v −1 , respectively. The optical and electrical properties of the CZTS thin films in relation to the secondary phases were discussed.

Phase evolution studies of mechanochemical-prepared Cu2ZnSnS4powder via comprehensive annealing and milling investigation

“…Similar to CIGS, the deposition methods of CZTS can be classified into two major categories of vacuum- and non-vacuum-based techniques. Thermal evaporation (Chalapathi et al , 2017), pulsed laser deposition (Cazzaniga et al , 2017), and sputtering (Zhou et al , 2017) are among the vacuum-based techniques, while the non-vacuum-based procedures are spray pyrolysis (Bouzida et al , 2021), SILAR (Banerjee et al , 2019), sol–gel (Müller et al , 2013), and spin-coating (Xiong et al , 2020). Unlike CIGS photovoltaic which possesses high efficiencies (Kamada et al , 2016), the power conversion efficiency (PCE) of CZTS thin-film solar cells is much lower than its theoretical limit (Shockley and Queisser, 1961).…”