Near-Infrared Luminescence Investigation of Cr4+ ions Doped Germanate

In this paper, the preparation of a series of Li2TiGe1-xCrxO5 phosphors by high-temperature solid-state reaction is reported. The results of X-ray diffraction show that the doping of Cr4+ ions makes the lattice expand to a larger size. X-ray photoelectron spectroscopy (XPS) analysis shows that the chromium ions in the sample are tetravalent, confirmed further by fluorescence spectroscopy. Under the excitation of 980nm laser, the Cr4+ ions 3T2 doped 3A2 radiates transition and emits light at 1300nm. At the same time, the luminescence lifetime decreases with the increase in Cr4+ ions doping concentration. Li2TiGe1-xCrxO5 phosphors have a broad application prospect in near-infrared LEDs.