Design of need-based phosphors and scintillators by compositional modulation in the ZnGa_2−xAl_xO₄:Cr³⁺ spinel: pure compound versus solid solutions

Abstract

Material which can depicts persistent near infrared (NIR) light under both ultraviolet (UV) and x-ray illumination can be boon to sustainable economy particularly for applications like optical imaging, solid state...

Tunable upconversion in ZnAl2−xGaxO4:Er,Yb phosphors by modulating the Al/Ga ratio and application in optical thermometry

“…Similar observations were found in the average positron lifetimes in Cr-doped solid solutions of ZnGa 2 O 4 and ZnAl 2 O 4 . 33 The average positron lifetime in the undoped samples is smaller than in the Er and Yb doped samples in all cases. The doping increased the average lifetime significantly in Al rich samples compared to the Ga rich samples.…”

“…2(a) that t 1 is nearly constant in all the cases but the fraction of positrons annihilating with this lifetime gradually decreases (I 1 in Fig. 2 33 The average positron lifetime in the undoped samples is smaller than in the Er and Yb doped samples in all cases. The doping increased the average lifetime significantly in Al rich samples compared to the Ga rich samples.…”

“…In one of our previous works though we have modulated the Ga/Al ratio in the same matrix for improved photo and radioluminescence of trivalent chromium. 33 Moreover, in the case of lithium doping in spinel-based UC materials, the lattice is under tremendous strain owing to size mismatch and also there might be a toxicity related issue on chromium doping.…”

Stabilization of Eu2+ in Li2B4O7 with the BO3 network through U6+ co-doping and defect engineering

“…3,4 Also, aliovalent doping and high-temperature treatment result in an abundance of defects, which have a profound influence on the various functionalities of materials. 5,6 Most of the lanthanides are stable in the +3 oxidation state, though some display +2 and +4 oxidation states (Eu 2+ , Sm 2+ , Yb 2+ and Tb 4+ ).…”

Energetic, Electronic, and Optical Behavior of Intrinsic Charge Carrier-Trapping Defects in Ge-Doped ZnGa2O4: Insights from a DFT Study

“…On the other hand, Byun et al reported blue, green, and red emission from undoped, Tb-doped, and Eu-doped ZnGa 2 O 4 , respectively . Cr-doped ZnGa 2 O 4, which is a red phosphorescence material, has been extensively studied because of its potentiality toward in vivo imaging. − Various efforts have been reported to improve the red long-lasting phosphorescence of Cr-doped ZnGa 2 O 4 by codoping with one or multiple elements. − Mn-doped ZnGa 2 O 4 has also attracted the attention of various groups due to its broadband emission varying from green to deep red. , Recently, Chen et al showed that visible to near-infrared photoluminescence of Mn-doped ZnGa 2 O 4 can be achieved by manipulating the valence of Mn . Castaing et al reported that ZnGa 2 O 4 can be used for optical memory applications after doping with Ni .…”