Study of morphological, structural, optical, and optoelectrical properties of novel AgGaGeS4 thin films synthesized by thermal evaporation procedure

In this research, we report the manufacture of neoteric AgGaGeS4 layers by the thermal evaporation method. The AgGaGeS4 layers exhibited orthorhombic structure, and the structural indices were evaluated using the Scherer formulas from the XRD data. Further, the surface study indicated that the AgGaGeS4 films have homogenous and uniform surfaces, while energy-dispersive X-ray spectroscopy (EDX) confirmed the compositional constituent percentages of the AgGaGeS4 layers. The optical properties of the AgGaGeS4 layers refer to improving the extinction coefficient, absorption coefficient, and refractive index by enlarging the layer thickness. In addition, the optical bandgap of the AgGaGeS4 layers was lowered from 1.67 to 1.46 eV by boosting the layer thickness. Furthermore, the skin depth of these layers diminished, whereas the absorption coefficient values revealed the opposite trend. On the other side, Miller's equations have been applied to assess nonlinear optical properties of the AgGaGeS4 layers, such as nonlinear refractive index and first and third-order nonlinear optical susceptibility. Moreover, the hot-probe method proved the p-type semiconducting characteristics of the AgGaGeS4 layers.