Green Emission in Thermally Stable Er<sup>3+</sup> Doped Lead-Free Perovskite Phosphor for Solid-State Lighting and Optical Thermometry Applications
Ishant Kumar, Avinash Kumar, Sandeep Kumar, Vikas Sangwan, Arvind K. Gathania
Abstract
CaTiO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> :xEr <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3+</sup> <underline xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">(0.1≤x≤7 mole %)</u> phosphor materials were meticulously prepared through the solution combustion method. Comprehensive analyses employing Powder X-ray Diffraction (PXRD), Field Emission Scanning Electron Microscopy (FESEM), and Fourier Transform Infrared Spectroscopy (FTIR) were conducted to investigate the phase, morphology, and vibrational characteristics of the synthesized phosphors. A detailed luminescence study was undertaken using photoluminescence spectroscopy, revealing distinctive 4f-4f transitions associated with Er <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3+</sup> in both excitation and emission spectra. The application of Dexter's theory provided insights into the quenching mechanism inherent in CaTiO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> :Er <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3+</sup> phosphors. Photometric studies were carried out to evaluate the suitability of the synthesized material for solid-state lighting applications. Furthermore, to assess the thermal stability of the phosphor material, the activation energy was computed. The fluorescence intensity ratio of thermally coupled energy levels of Er <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3+</sup> ion was utilized to assess the temperature-sensing capabilities of the synthesized material. This material may be suitable for solid-state lighting and optical thermometry applications.