Optical properties of thin Cu2ZnSnS4, films produced by RF magnetron sputtering

Optical properties of thin Cu2ZnSnS4 films produced by RF magnetron sputtering of preliminarily synthesized material are studied. Transmission and reflection coefficients are studied in a range from 0.4 to 26 μm. The optical band-gap width depending on substrate temperature is estimated; in optimal modes, it is equal to 1.47 eV. The study of electrical properties shows that Cu2ZnSnS4 possesses low charge-carrier mobility, μ = 1.9 cm2/(V s), at room temperature and hole concentration р = 5 × 1018 cm–3. Electron microscopy shows that the film possesses a polycrystalline structure with a crystallite size on the order of 100 nm.