Rare-earth-free Mn⁴⁺ ions activated Ba₂YSbO₆ phosphors for solid-state lighting, flexible display, and anti-counterfeiting applications

Recenlty, rare-earth (RE)-free ions (Mn⁴⁺) activated phosphor materials are becoming an alternative source while replacing Eu²⁺ ions activated metal oxide, phosphate, and nitride phosphors for multi-functional applications. In this report, we prepared novel RE-free Mn⁴⁺ (mol%) ions activated double perovskite-type Ba₂YSbO₆ (BYSO:Mn⁴⁺) phosphor materials by a solid-state reaction method in an ambient condition. The physicochemical properties such as phase purity, elemental composition, and morphology of the materials were systematically investigated. The temperature-dependent photoluminescence (PL) properties of the BYSO:8 mol% Mn⁴⁺ (i.e., BYSO:8Mn⁴⁺) phosphor samples were studied. The PL excitation of the phosphors showed a broadband spectrum in the near-ultraviolet region from 300 to 450 nm with a maximum intensity at 353 nm. Under 353 nm excitation, the Mn⁴⁺ ions activated phosphors showed a broadband far-red emission in the region of 650–750 nm with a maximum intensity at 694 nm due to the ²E_g→⁴A_2g electronic configuration. The BYSO:8Mn⁴⁺ phosphors also showed a lower intensity band at 667 nm and the corresponding Commission Internationale de l'Eclairage chromaticity coordinate for the optimized phosphor was (0.653, 0.274) which is more beneficial, especially for the growth process in plants. Additionally, the optimized BYSO:8Mn⁴⁺ phosphor maintained good thermal PL behavior and its related binding energy value was 0.29 eV. Considering these good benefits from the BYSO:8Mn⁴⁺ phosphor, we further fabricated a red light-emitting device to demonstrate its potential applicability in solid-state lighting. Also, the as-prepared polydimethylsiloxane composite films demonstrated their suitability for flexible display and anti-counterfeiting applications in harsh environmental conditions.