Twitching inherent properties of Sm3+ ions doped BaZrO3 nanophosphors for optoelectronic application

Abstract

In this study, we report the synthesis and comprehensive characterization of undoped and samarium (Sm³⁺) doped barium zirconate (BaZrO₃) nanophosphors with varying Sm³⁺ concentrations (2, 5, and 10 wt%), prepared via the sol-gel auto-combustion method. The primary aim of this work is to develop high-performance, Sm³⁺-activated BaZrO₃ nanophosphors with enhanced optical and electrical functionalities for next-generation optoelectronic applications. Though BaZrO₃ is well known for its thermal stability and dielectric properties, its potential as a host matrix for rare-earth (RE) doped luminescent materials remains underexplored. This study seeks to fill that gap by investigating the structural, optical, and dielectric response of Sm³⁺-incorporated BaZrO₃ nanophosphors. A suite of advanced analytical techniques was employed to elucidate the physicochemical properties of the synthesized nanophosphors. X-ray diffraction (XRD) confirmed the phase purity and revealed a decreasing crystallite size from 47 nm to 20 nm with Sm³⁺ doping concentration. Fourier-transform infrared (FTIR) and Raman spectroscopy validated the vibrational characteristics and local bonding environment of the host-dopant system. Elemental distribution were examined using energy dispersive X-ray spectroscopy (EDX). High-resolution transmission electron microscopy (HRTEM) confirmed the nanoscale dimensions and moderate agglomeration. Dielectric spectroscopy and impedance analysis demonstrated that ionic conductivity improved with reduced bulk resistance, indicating potential for solid-state electrolyte applications. Optical studies using ultraviolet–visible diffuse reflectance spectroscopy (UV–Vis DRS) revealed a decrease in bandgap values from 3.64 eV to 3.52 eV with Sm³⁺ doping concentration, thereby enhancing the optical properties of prepared nanophosphors. Furthermore, photoluminescence (PL) spectroscopy under 403 nm excitation revealed three intense emission bands at 540 nm (green), 600 nm (orange-red), and 644 nm (red). Notably, the 10 wt% Sm³⁺ doped nanophosphors exhibited a high colour purity of 90.57 %, emphasizing its suitability for high-quality luminescent applications. The novelty of this work lies in the strategic doping of Sm³⁺ into the BaZrO₃ lattice to simultaneously tailor its photoluminescent and electrical behaviour, an approach that expands the multifunctional capabilities of this perovskite material. These findings suggest that Sm³⁺ doped BaZrO₃ nanophosphors act as a promising material for applications in optoelectronic devices, particularly in solid-state lighting and display technologies.