Red light component tuning by n-UV/blue light excitations in Sm3+/Eu3+ co-doped Y2O3–Al2O3–Bi2O3–B2O3–SiO2 glasses for W-LED applications

Abstract

A series of single (Sm3+, Eu3+) and co-doped (Sm3+- Eu3+) Yttrium alumino bismuth borosilicate (YABiBS) glasses have been prepared by basic melting quench method and the emission properties of synthesized glasses were investigated. To analyze the optical and energy transfer mechanism of these glasses the characterizations viz, absorption and luminescence are done. The absorption spectral data is used to observe the electronic band structure by direct and indirect optical band gaps. Bonding Parameters (β‾,δ) were evaluated to explain the ionic (or) covalent nature of the metal-ligand bonds in the present glass network. Near ultraviolet (n-UV) and blue excitations such as 392 nm, 400 nm, 457 nm, and 488 nm are used to record the emissions of single (Sm3+) and co-doped (Sm3+-Eu3+) glasses to achieve the tuneable emissions. Sm3+ ions show the reddish-orange emission mainly through 4G5/2 → 6H7/2 (597 nm) and Eu3+ ions show the intense red emission of transition 5D0 → 7F2 (612 nm). For the Sm3+-Eu3+ glasses by using different excitations, we will achieve the emission changes from orange to reddish-orange and then to red. Decay curves were analysed to know the process of interaction involved in the energy transfer among co-doped RE3+ ions. CIE coordinates and CCT values for all the prepared glasses by various excitations were calculated.