Sr_1.0Mg_2.0B₆O₁₂:0.5Sm³⁺ phosphor for yellowish-orange light emission

This study aims to investigate the spectroscopic properties of a Sr_1.0Mg_2.0B₆O₁₂:0.5Sm³⁺ phosphor synthesized using a solid-state reaction method. With the aid of scanning electron microscopy and energy-dispersive X-ray spectroscopy, the morphology and elemental composition of the phosphor were determined. X-ray diffraction is utilized for the study of phase changes and crystallite phases in phosphor. The energy bandgap and bonding nature of the phosphor were examined using the absorption spectrum. The optical energy bandgap of Sr_1.0Mg_2.0B₆O₁₂:0.5Sm³⁺ phosphor is found to be 4.942 eV for a direct allowed transition and 4.79 eV for an indirect allowed transition. The presence of ionic bonding nature in phosphor was obtained from the nephelauxetic ratios by analysing the absorption peaks. Oscillator strengths of the absorption peaks were estimated. Photoluminescence of the sample was studied, and colorimetry analysis was done to identify the emission colour. From the results, the colour of light emitted from the sample was confirmed to be yellowish-orange and the colour temperature is obtained as 3438 K. (author)