Mathematical Models to Determine the Conductivity of a Cztis Photovoltaic Material as a Function of the Synthesis Temperature

Abstract

Study on the conductivity of the material Cu2ZnTiS4 (CZTiS), obtained under a hydrothermal route from precursor nitrates treated in a teflon reactor under constant pressure with a stainless steel jacket, involving different heat treatments (200, 225, 250, 275 and 300°C) for reaction times of 48 hours in all cases and subsequent calcination at 550°C in a tube oven, under nitrogen flow (50 mL min-1). The materials were characterized by X-ray Diffraction (XRD), Raman spectroscopy, Scanning Electron Microscopy (SEM), and Atomic Force Microscopy (AFM). The results showed materials with structural and crystalline properties concordant with a kesterite type phase, evidencing homogeneous surfaces, unique morphological properties derived from the process with regular distribution of particles and size of the nanometric order (5-6 nm) as well as the characteristics of the roughness of the material. Solid state impedance spectroscopy (IS) evidenced its electrical behavior and validated the proposed mathematical models.