Innovative synthesis, structural characteristics, linear and nonlinear optical properties, and optoelectric parameters of newly developed A2ZnGeO4 (A = K, Li) thin films

Abstract

The synthesis of high-quality thin films through spin coating deposition on meticulously cleaned glass substrates is presented. Optical band gaps E_g of both samples using the Kubelka–Munk function are determined. The data analysis uncovers the presence of optical allowed direct transition for A₂ZnGeO₄ (A = K, Li). Spectroscopic ellipsometry measurements on A₂ZnGeO₄ (A = K, Li) thin films and an analysis of their optical properties using the Cauchy model are presented. Furthermore, the increase of the thickness of the thin film results in improvements in their optoelectrical parameters, such as electrical conductivity, optical mobility, and optical conductivity. Using the Kubodera and Kobayashi comparative model, the third order nonlinear susceptibility (χ⁽³⁾) was estimated based on the compounds' high linear absorption of the generated third harmonic wavelength (355 nm). This paper presents remarkable NLO results that reveal potential uses in optoelectronics and photonics.