Investigations on the luminescence and gamma ray shielding features of Pr3+: BLCZFB glass for orange-red laser and radiation applications

Abstract

Praseodymium (Pr3+) ions doped barium lithium calcium zinc fluoroborate (BLCZFB) glasses were prepared with the melt quenching technique, and their physical, optical, and shielding properties were estimated. Their amorphous nature was verified with X-ray diffraction (XRD) pattern. Each of their absorption spectra exhibited nine peaks in the visible and near infra-red (NIR) regions. The absorption bands of oscillator strength and Judd-Ofelt (J-O) parameters were used to evaluate their radiative parameters. Their predominant emission peak in their visible emission spectra was observed at 604 nm (16556 cm−1), attributed to 1D2→3H4 transition. And their main emission peak in the NIR emission spectra was at the wavelength of 1458 nm (6858 cm−1), corresponding to the 1D2→1G4 transition. Their spectroscopic properties, including the stimulated emission cross-section (σPE), branching ratio (βR), quantum efficiency (η), gain bandwidth (σPE×Δλeff), and optical gain parameter (σPE×τexp) were also calculated for the visible (1D2→3H4) and NIR (1D2→1G4) emission transitions. From their emission spectra, the color chromaticity coordinates, (x, y) and (u, v), the color purity (CP), and the correlated color temperature (CCT) were calculated. The concentration quenching mechanism and energy transfer process were also explored from the emission spectra. Both the visible and the NIR lifetime curves exhibited non-exponential behaviour for all the glasses. The experimental lifetime decreases with the increase of Pr3+ ions concentration, which could be attributed to the cross-relaxation channels. The decay profiles are well fitted with Inokuti-Hirayama (IH) model (S = 6) to realize the energy transfer process. The energy transfer parameter (Q), donor-acceptor interaction parameter (CDA), and critical distance (R0) were also calculated. Next, the direct and indirect allowed transitions, the band tailing (B), and Urbach parameters (ΔE) were calculated. Then the shielding parameters, including the mass attenuation coefficient (MAC), the mean free path (MFP), and the equivalent atomic number (Zeq), etc., were articulated. Based on the above parameters, 1PrBLCZFB and 2PrBLCZFB glasses are suggested to be used for future solid-state orange-red laser, photonic devices, optical amplifier, and gamma ray shielding.