Study of the Frequency Modulations on the Optical and Structural Characteristics of Electrodeposited Ni-Doped PbTe Thin Films

Abstract

This report presents the successful fabrication and characterization of nickel-doped lead telluride (Ni:PbTe) chalcogenide thin films for potential device applications. The films were synthesized using a three-electrode electrodeposition method on fluorine-doped tin oxide (FTO) glass substrates, with lead trinitrate (V), tellurium (IV) oxide, and nickel chloride hexahydrate serving as precursors. Deposition time was varied to optimize film properties. Characterization using UV-Vis spectrometry and X-ray diffraction (XRD) revealed that absorbance increased with deposition time across the visible (VIS) and near-infrared (NIR) regions. The refractive index ranged from 1.5–1.62 at 1-minute deposition, increasing to 2.5–3.25 at 4 minutes, indicating suitability for optoelectronic devices like optical fibers and waveguides. Transmittance decreased with longer deposition times but remained higher in the NIR region. The optical bandgap ranged from 1.3–1.7 eV across different deposition times ideal for photovoltaic and LED applications. Film thickness also increased with deposition time, suggesting that optical properties can be tuned accordingly.XRD analysis confirmed the crystalline nature of the films, with crystallinity improving at longer deposition durations. Structural parameters such as crystallite size, dislocation density, and microstrain supported this trend, reinforcing the films' potential for advanced optoelectronic applications.