Noncytotoxic Dy3+-activated glass emits cool white light for near ultraviolet-based white light-emitting diodes, visible lasers, and biomedical applications

Using the melt quenching technique, a lithium zinc borate glass (LZB) system with trivalent dysprosium ions (Dy3+) was synthesized, and the luminescence and lasing properties of these materials were examined for the generation of white light. Structural investigation through X-ray diffraction revealed that the prepared glass had an amorphous nature. The optimized glass containing 0.5 Dy3+ had a direct optical band gap of 2.782 eV and an indirect optical band gap of 3.110 eV. A strong excitation band at 386 nm (H-6(15/2)& RARR;I-4(13/2)) was recognized in the ultraviolet (UV) light region of its excitation spectrum. Emission bands could be seen in the photoluminescence spectrum at 659, 573, and 480 nm under the 386 nm excitation. These transitions of emission resembled electronic transitions such as (F-4(9/2)& RARR;H-6(11/2)), (F-4(9/2)& RARR;H-6(13/2)), and (F-4(9/2)& RARR;H-6(15/2)). In a pristine glass matrix, the higher intensity ratio of yellow to blue can result in the production of white light. The optimized Dy3+ ion concentration was observed to be 0.5 mol%. In addition, an analysis of lifetime decay was conducted for all synthesized glasses, and their decay trends were systematically investigated. Noticeably, we assessed the photometric parameters and found that they were close to the white light standard. Furthermore, a cytotoxicity study was carried out using lung fibroblast (WI-38) cell lines for the optimized 0.5Dy(3+)-doped LZB glass and it appeared to be noncytotoxic. It is clear from the results that the noncytotoxic LZB glass doped with 0.5 Dy3+ ions could be a suggestive choice for the manufacture of white light-emitting diodes and lasers using near-UVs.

Automated summary

By using the melt quenching technique, a lithium zinc borate glass with trivalent dysprosium ions (Dy3+) was synthesized, and its luminescence and lasing properties were investigated for white light generation. The synthesized glass was found to be amorphous according to the X-ray diffraction analysis. The optimized glass with 0.5 Dy3+ doping concentration exhibited a direct optical band gap of 2.782 eV and an indirect optical band gap of 3.110 eV. The photoluminescence spectrum showed emission bands at 659, 573, and 480 nm under 386 nm excitation, which were attributed to electronic transitions. The noncytotoxicity of the optimized Dy3+-doped LZB glass was confirmed through a cytotoxicity study using lung fibroblast cell lines. The results suggest that this glass could be a promising choice for white light-emitting diodes and lasers.