Luminescent properties and structure of Pr3+ - doped multi-component transparent lead zinc borate glasses for red LEDs

Present study reveals the effects of varying concentrations of Pr 2 O 3 on the Spectral characteristics of 35PbO-60-xB 2 O 3 -5ZnO-xPr 2 O 3 (x = 0.5–3mol%) glasses, which were prepared using the melt-quench technique. The XRD and Raman results confirm that the glasses possessed the amorphous nature with borate complexes as the main structure units. From the absorption spectrum , the glass has a strong absorbance in the visible and infrared regions. The theoretical and experimental oscillator strengths ( f exp and f c a l ), phenomenological parameters (Ω 2 , Ω 4 , Ω 6 ) of Pr 3+ were calculated using the Judd-Ofelt theory. Strong emissions in the reddish orange region at 600 nm was observed due to the transitions of Pr 3+ ions from 1 D 2 → 3 H 4 at 444 nm excitation. The optimal concentration of Pr 2 O 3 in the glass is 1 mol%, exhibiting the highest photoluminescence intensity and the second longest decay time (microsecond order). The decay time reduction with increasing Pr 2 O 3 content, indicates the presence of resonant energy transfer between Pr 3+ ions. Therefore, the Pr 3+ -dope lead zinc borate glasses could be used for red LED.