Investigation of Photo Sensitive Properties of Ferroelectric Stannous Chloride Dihydrate Doped Triglycine Sulphate (SnCl2.2H2O-TGS) Crystal by Pseudo Spin Lattice Coupled Mode (PLCM) Model

Abstract

A modified theoretical model based on a time, temperature dependent Green’s function formalism has been constructed by integrating the Pseudo-Spin Lattice Coupled Mode (PLCM) approach with the Ising spin framework to investigate ferroelectric characteristics in stannous chloride dihydrate doped triglycine sulphate (SnCl₂.2H2O-TGS) crystal. The formulation incorporates renormalized boundary condition for polarization, explicitly accounting for phonon anharmonicity up to the fourth order, together with coupling contributions from an externally applied electric field. This model has been utilized to analyze the second-order phase transition behaviour of SnCl₂.2H2O doped TGS, offering a detailed theoretical perspective on its ferroelectric phase stability. In addition, the work evaluates the photoactive performance parameters of the doped system, particularly emphasizing the photosensitivity figure of merit (M₁), high-current responsivity (M₂), vidicon suitability factor (M₃) and their corresponding ratios M₂/M₁, M₃/M₂ and M₃/M₁ under both bias-free and externally biased field environments. The findings underscore that higher-order anharmonic lattice interactions and polarization-field coupling significantly contribute to the tunability and enhancement of the electromechanical and optoelectronic behaviour of stannous chloride dihydrate doped triglycine sulphate (SnCl₂.2H2O-TGS) crystals, thereby demonstrating their potential for advanced ferroelectric and photosensitive device applications.