Near‐Infrared Emitting Nd 3+ :LaF 3 Nano‐Glass‐Ceramics Produced by Sol–Gel Technology

ABSTRACT In this work, the series of sol–gel materials doped with Nd 3+ ions were synthesized and further transformed into nano‐glass‐ceramics containing LaF 3 :Nd 3+ nanocrystals via controlled heat treatment, carried out at 700°C and 900°C. The structural characterization of materials obtained at different temperature conditions was performed using x‐ray diffraction analysis (XRD), revealing a crystallization of the fluoride nanophase. The examination of luminescent properties included analysis of PLE and PL spectra recorded using different excitation wavelengths. The characteristic emission bands of Nd 3+ ions within near‐infrared (NIR) spectral scope were observed for all fabricated samples. Furthermore, the luminescence decay curves of the 4 F 3/2 state of Nd 3+ were registered. It has been demonstrated that samples annealed at a higher temperature level (900°C) exhibited more intense NIR luminescence bands and longer lifetimes of the 4 F 3/2 excited state, compared with the series fabricated at 700°C. Indeed, the luminescence lifetimes noted for materials annealed at 700°C ranged from 141 to 772 μs, whereas those obtained for materials heat‐treated at 900°C ranged from 213 to 862 μs. Based on the obtained results, it was concluded that the Nd 3+ ions were partially incorporated into LaF 3 nanocrystals, thus the fabricated sol–gel materials are promising candidates for the NIR luminescence applications.