Non‐cytotoxic Dy3+ activated glasses emit cool white light for NUV‐based WLEDs, visible lasers and biomedical applications

Using the melt quenching technique, lithium zinc borate glass system with trivalent dysprosium ions (Dy3+ ) have been 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 glasses have an amorphous nature. The optimized glass containing 0.5 Dy3+ has 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 (6 H15/2 →4 I13/2 ) has been recognized in the UV region of its excitation spectrum. Emission bands can be seen in the photoluminescence spectrum at 659 nm, 573 nm, and 480 nm under the excitation of 386 nm. These transitions of emission show a resemblance to electronic transitions such as (4 F9/2 →6 H11/2 ), (4 F9/2 →6 H13/2 ), and (4 F9/2 →6 H15/2 ). 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 they were close to the white light standard. Furthermore, the cytotoxicity study was carried out using lung fibroblast (WI-38) cell lines for the optimized 0.5Dy3+ : LZB glass and it appears to be non-cytotoxic. It is clear from the results that the non-cytotoxic LZB glass doped with 0.5 Dy3+ ions could be a suggestive choice for the manufacture of white LEDs and lasers using NUVs.