Investigation of structural, optical and luminescence characteristics of Dy3+-embedded alkaline heavy metal zincfluoroborophosphate glasses

Dy 3+ -embedded glasses have been widely considered for light-emitting diode applications as well as optical display devices. Based on this importance, the present study investigates the structural and photoluminescence characteristics of Dy 3+ -embedded zincfluoroborophosphate glasses. These glasses with molar composition of 35H 3 BO 3 + 10NH 4 H 2 PO 4 + 25BaCO 3 + (5 − N )La 2 O 3 + 25ZnF 2 + NDy 2 O 3 (BPBaLaZfDy N ), where N = 2.0, 1.0, 0.5, 0.1, and 0.05, were fabricated by the melt and quenching procedure. FTIR spectra show the existence of fundamental groups such as BO 3 and BO 4 units, phosphates as well as OH groups. The criterion of metallization, optical electronegativity and basicity of the fabricated glasses was investigated and presented. The three phenomenological Judd–Ofelt (JO) parameters were estimated with the aid of optical absorption of oscillator strengths by using well-known theoretical JO model and in turn estimated the essential radiative characteristics of excited fluorescent states of Dy 3+ ion. Dy 3+ :BPBaLaZfDy glasses reveal the luminescence levels at 840 nm (infrared: 4 F 9/2 → 6 H 7/2 ), 754 nm (infrared: 4 F 9/2 → 6 H 9/2 ), 664 nm (weak red: 4 F 9/2 → 6 H 11/2 ), 485 nm (blue: 4 F 9/2 → 6 H 15/2 ) and 576 nm (yellow: 4 F 9/2 → 6 H 13/2 ), exciting at 350 nm. Among different concentrations, 0.5 mol% (BPBaLaZfDy 0.5 ) glass exhibits relatively more intense emission for 4 F 9/2 → 6 H 15/2 , 13/2,11/2 transitions. From emission data, colour chromaticity coordinates, yellow/blue emission intensity ratio, colour purity and correlated colour temperatures have been determined. The decay times for BPBaLaZfDy glasses were measured with 350 nm excitation and noticed that the radiative de-excitation from 4 F 9/2 → 6 H 13/2 state. The fluorescence lifetime values decrease (659 μs to 389 μs) with increase (0.05 to 2.0 mol%) in Dy 3+ content. The analysis of the present work confirms the preference of BPBaLaZfDy glasses for the fabrication of optical display components as well as white light luminescence devices.