Characterization of GAGG Doped with Extremely Low Levels of Chromium and Exhibiting Exceptional Intensity of Emission in NIR Region

Abstract

Cerium and chromium co-doped gadolinium aluminum gallium garnets were prepared using sol-gel technique. These compounds potentially can be applied for NIR-LED construction, horticulture and theranostics. Additionally, magnesium and calcium ions were also incorporated into the structure. X-ray diffraction data analysis confirmed the all-cubic symmetry with an Ia-3d space group, which is appropriate for garnet-type materials. From the characterization of the luminescence properties, it was confirmed that both chromium and cerium emissions could be incorporated. Cerium luminescence was detected under 450 nm excitation, while for chromium emission, 270 nm excitation was used. The emission of chromium ions was exceptionally intense, although it was determined that these compounds are doped only by parts per million of Cr3+ ions. Typically, the emission maxima of chromium ions are located around 650–750 nm in garnet systems. However, in this case, the emission maximum for chromium is measured to be around 790 nm, caused by re-absorption of Cr3+ ions. The main observation of this study is that the switchable emission wavelength in a compound of single phase was obtained, despite the fact that doping with Cr ions was performed in ppm level, causing an intense emission in NIR region.

Insights into the Relationship between Crystallite Size, Sintering Pressure, Temperature Sensitivity, and Persistent Luminescence Color of Gd2.97Pr0.03Ga3Al2O12 Powders and Ceramics

“…It may be caused by the unintentional Cr 3+ admixture appearance in the structure which is an impurity from the Al precursor used for the synthesis. As the infrared emission has been observed in the GGAG structure even at extremely low concentrations of Cr 3+ (15 ppm), 44 the luminescence observed at low temperatures was assigned to the Cr 3+ impurities from the precursor.…”

Enhancing Infrared Photoluminescence Performance via Li+ Substitution and Yb3+ Codoping in Na3ScSi3O9:Cr3+ Phosphor

“…As an indispensable component in phosphor-converted infrared LEDs, infraredemitting phosphors play a crucial role in determining the overall luminescence performance of the final infrared LED devices [10]. In recent years, Cr 3+ -activated broadband inorganic phosphor materials have attracted extensive attention in view of their superior infrared luminescence performance, including strong blue light absorption capability and tunable broadband emission in a weak octahedral crystal field [11][12][13][14][15][16][17]. Among them, Cr 3+ -doped silicate-based broadband infrared phosphors usually show good physicochemical stability, low cost, and high luminescence efficiency [18][19][20], which enables them to be desirable light conversion materials for phosphor-converted infrared LEDs.…”

Advances in Functional Inorganic Materials Prepared by Wet Chemical Methods

“…The grain size increased drastically with an increase of BiMnO 3 , moreover, the gradual increase of the BiMnO 3 content resulted in noticeably higher magnetization values. Finally, using the sol-gel method, Inkrataite et al [3] prepared cerium and chromium co-doped gadolinium-aluminum-gallium garnet (GAGG, Gd 3 Al 2 Ga 3 O 12 ). The remarkable feature of this study is that an exceptionally intense emission in the near-infrared region (NIR) was achieved with an extremely low doping level.…”