Judd-Ofelt analysis and visible luminescence of Sm3+: MCZBP glass for reddish-orange laser and multi-colour display applications

Abstract

A new series of Sm3+ ions doped magnesium cadmium zinc borophosphate (Sm3+: MCZBP) glasses were prepared with melt quenching, and were characterized with X-ray diffraction, optical absorption spectra, excitation spectrum, emission spectra, and fluorescence decay curves. The increase of Sm3+ ions concentration increased the density (ρ), refractive index (n) and decreased the molar volume (Vm) of the glass. The non-metallic nature was identified from the metallization factor (M). The optical absorption spectra were used to understand the optical band gap (direct and indirect). The oscillator strength and Judd-Ofelt (JO) intensity parameters were determined from the optical absorption spectra and further used to evaluate the radiative properties of the Sm3+ ions doped glasses. The luminescence spectra showed the four emissions from transitions 4G5/2→6HJ (J = 5/2, 7/2, 9/2, and 11/2), corresponding to 562 nm (17793 cm−1), 597 nm (16750 cm−1), 644 nm (15527 cm−1) and 704 nm (14204 cm−1) upon exciting with 401 nm (24937 cm−1) wavelength, respectively. CIE chromaticity co-ordinates (x, y), the colour purity (CP), and the correlated colour temperature (CCT) values were calculated, showing that the emission colour fell in the reddish-orange region. The experimental lifetime (τexp), quantum efficiency (η), stimulated emission cross-section (σPE), gain bandwidth (σPE×Δλeff), and optical gain parameter (σPE×τexp) were articulated from the emission spectra of the glasses. The decay curves of 4G5/2 excited state exhibited non-exponential profile for all the present glasses. The efficient energy transfer between two Sm3+ ions through cross-relaxation was analysed with Inokuti-Hirayama (IH) model (S = 6). All the absorption and spectroscopic results revealed that 1SmMCZBP glass had a strong reddish-orange emission at 597 nm corresponding to 4G5/2 → 6H7/2 transition, and could be very promising material for laser and multi-colour display.