The optical characteristics and co-evaporation processing of CuInGaSe2 thin film

CuInGaSe2 crystals were synthesized using the traditional melt method. Various thicknesses of thin films were formed on glass substrates at room temperature using the thermal evaporation method. In the wavelength range of 250–2500 nm, the optical absorption spectra of thin films were examined. To calculate the optical band gap of the films, Taucs’ relation was applied. Calculations were made to determine how the film thickness affected the energy gap of CuInGaSe2 thin films. Estimation have been made to show fluctuations in the direct optical band gap values with variations in film thickness, but the indirect band gap energy varies systematically with thickness. © The Author(s) 2023.