Thin films of copper doped tin sulphide (CuxSn1−xSy) with the complexing agent TEA are deposited on glass substrates by SILAR technique for various molar concentrations (0.01–0.10 M) at room temperature. The structural, surface morphology, topography and optical properties of the films are studied for the varying molar concentrations. XRD studies reveal the amorphous nature of TEA added Cu doped SnS films. The surface morphology was observed by SEM images. Surface topography of the film is studied by AFM. 2D-AFM images reveals that the grain size, surface roughness and height decreases for the increasing concentration. FTIR analysis shows the molecular vibrations. The optical properties of the deposited films are investigated by measuring the optical absorbance of the films in a range of 300–800 nm with a UV–Vis spectrophotometer. Other properties such as transmittance, refractive index, and energy gap are calculated. Based on the above characterisations, synthesized TEA added copper doped tin sulphide thin film may be used for small band-gap semiconductors, non-linear materials and photovoltaic cell materials.