Near-Infrared Luminescence Investigation of Cr4+ ions Doped Germanate

Abstract

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.

A formulation design and preparation of gold‐free purple of Cassius based on the doped malayaite

“…A major peak at 579.21 eV and a minor peak at 588.41 eV can be assigned to Cr(IV) (Figure 2D). [35][36][37][38] In the samples with a low Ca/Sn molar ratio (Figure 2C), the relative content of Cr(IV) is higher than that of Cr(III); conversely, the relative content of Cr(IV) is significantly higher than that of Cr(III) (Figure 2D). Theoretically, F I G U R E 2 (A-H) X-ray photoelectron spectroscopy (XPS) images of samples 2# and 6# calcined at 1100 • C for 1 h when Cr(IV) replaces more Sn(IV) in CaSnSiO 5 , there will be less Cr(IV) covering the surface (Figure 2C).…”