Tailoring the structural, optical, and optoelectrical parameters of the thermally evaporated Ag2FeGeSe4 thin films

In this paper, the thermal evaporation approach has produced successful innovative Ag₂FeGeSe₄ layers at various thicknesses (183, 220, 346, and 455 nm). According to the structural findings, the Ag₂FeGeSe₄ samples are polycrystalline and feature an orthorhombic phase. The FESEM analysis indicated that the Ag₂FeGeSe₄ layers had a uniform grain structure. On the other side, the Ag₂FeGeSe₄ layers were created with a respect ratio almost precisely the same as the ingots, according to the EDX data. The optical results demonstrated that the energy gap of the Ag₂FeGeSe₄ layers was detected to reduce as the layer thickness was expanded. In distinction, the Urbach energy values of the Ag₂FeGeSe₄ layers displayed the opposite tendency. Numerous parameters have been estimated and studied, including the refractive index, optical dielectric constant, absorption coefficient, extinction coefficient, and optical conductivity. Also calculated and discussed were the oscillator energies, dispersion, and refractive dispersion indices of the Ag₂FeGeSe₄ layers. The nonlinear optical characteristics are improved by similarly raising the film thickness. We examined the behaviour of Ag₂FeGeSe₄ layers as semiconductors using the hot-probe technique and a negative voltage. This film’s propensity for p-type semiconductor behaviour was discovered.