Fabrication of K₂O–Al₂O₃–Gd₂O₃–P₂O₅ glasses for photonic and scintillation materials applications

Dysprosium (Dy³⁺) doped glasses of the potassium aluminum gadolinium phosphate (KAGP) were fabricated by melt-quenching technique. The preparation of glasses was varied the concentrations of Dy₂O₃ at 0.00, 0.05, 0.10, 0.50, 1.00 and 3.00 mol%. The physical and spectroscopic properties were investigated for white light emitting devices. The absorption spectra were attributed to Dy³⁺ transitions from the ⁶H_15/2, ground state to the various excited states and found that the intensity of absorption spectra was increased with increasing Dy₂O₃ concentration. The Judd-Ofelt (JO) intensity parameter Ω_λ (λ = 2, 4 and 6) were estimated from the absorption spectra of 0.50 mol% Dy₂O₃ doped KAGP glass and found to be Ω₂ > Ω₄ > Ω₆. The photoluminescence (PL) spectra were record under 350 nm and showed four intense peaks at 482, 573, 664 and 753 nm which correspond to the excited states (⁴F_9/2) to ⁶H_15/2, ⁶H_13/2, ⁶H_11/2 and ⁶H_9/2 respectively. The intensity of emission spectra increased with content of Dy³⁺ ions until 0.5 mol% in KAGP glasses and beyond concentration quenching was observed. From the emission spectra have evaluated chromaticity co-ordinates CIE 1931 and observed that the emission of KAGP glasses was in the white region. The results approve that the Dy³⁺ doped KAGP glasses could be considered for optoelectronic devices such as lasers and white light emitting diode (w-LEDs). The radioluminescence (RL) spectra were measured and show the strongest emission from X-rays excitation at 0.5 mol% of Dy₂O₃. In evaluation of scintillation property between 0.50 mol% of Dy₂O₃ doped KAGP glass and BGO crystal, the integral scintillation efficiency was 9% of BGO. It can be potential for integration mode of scintillation such as in medical and industrial X-ray imaging applications.