The luminescence properties of stable halide double perovskites Cs2BIInCl6, where BI – 40 % Ag, 60 % Na, doped with Sb³⁺ and Er³⁺ in the region 250-1600 nm, were investigated for the first time and reveal significant potential for advanced applications. We employed Scanning Electron Microscopy, X-ray Diffraction, and Raman Spectroscopy, which provided insights into the morphology, crystal structure, and vibrational characteristics of the samples. The excited Sb³⁺ ions emit blue light at 450 nm due to electronic absorption at sub-band gap levels, facilitating energy transfer to Er³⁺ ions. Notably, the Er³⁺ emit radiation at 1540 nm, a wavelength particularly advantageous for optical communication applications. Additionally, emissions at 525 nm, 552 nm, 665 nm and 805 nm are observed, corresponding to f-f transitions of Er³⁺ ions. Leveraging the synthesised materials, we successfully have developed a LED prototype that utilizes a UV chip (320 nm) combined with the Cs2Ag0.4Na0.6In0.9Er0.01Sb0.09Cl6 powder as a stable and effective luminophore for possible application in optoelectronics.
