Judd-Ofelt itemization and influence of energy transfer on Sm3+ ions activated B2O3–ZnF2–SrO–SiO2 glasses for orange-red emitting devices

Abstract

Augmenting the photoluminescence (PL) properties of Samarium (Sm3+) doped Zinc Strontium fluoro-borosilicate glass (ZSFBSi glass) by varying the Sm3+ ions concentration unlocks new prospects for their application as luminescent devices. This paper presents absorption, photoluminescence (PL), energy transfer and color chromaticity parameterization of ZSFBSi glass doped with Sm3+ ions concentrations. The Judd-Ofelt (J-O) theory in correlation with absorption as well as PL spectra leads to the estimation of radiative parameters of the excited luminescent states of Sm3+ ions needed to understand the luminescent potentiality of the as-prepared glasses. The absorption spectral data reveals the nature of bonding between Sm3+ ions and oxygen ligands in the as-quenched glasses as ionic and the result is consistent with the J-O analysis. The PL spectra of as-quenched glasses exhibit greenish-yellow, orange-red, light red and red color ascribed to 4G5/2 → 6H5/2, 6H7/2, 6H9/2, 6H11/2 emission bands at 563, 599, 646 and 706 nm, respectively. The PL intensity enhances with an escalation in Sm3+ ions content until 1.0 mol% and reduces thereafter, owing to a proficient energy transfer (ET) process. The Dexter theory and Inokuti-Hirayama (I–H) model identified the foremost ET process associated with the as-quenched glasses as dipole-dipole in nature. The CIE color coordinates (x, y) and Correlated Color Temperature (CCT) were calculated to cognize the effectiveness of as-quenched glasses in radiative cool white emission. The estimated branching ratios, emission cross-sections, gain bandwidth, quantum efficiency, optical gain, color coordinates and CCT finally reveals that the as-quenched glasses can be used in luminescent devices and amide all, 1.0 mol% Sm2O3 in ZSFBSi glass is highly appropriate for white LEDs as well as orange-red luminescent devices.