Synthesis, luminescence properties and energy transfer of Ca2MgWO6:Cr3+,Yb3+ phosphors

Influence of Cr3+ on yellowish‐green UC emission and energy transfer of Er3+/Cr3+/Yb3+ tri‐doped zinc silicate glasses

“…Here, all the absorption spectra of Er 3+ , Cr 3+ , and Yb 3+ are observed in the absorption spectra of Er 3+ /Cr 3+ /Yb 3+ tri‐doped. At the same time, we can see the strong absorption spectra of Er 3+ /Cr 3+ /Yb 3+ tri‐doped bands centered around 440 and 650 nm due to the overlap between the 4 A 2g → 4 T 1g ( 4 F), and 4 A 2g → 4 T 2g ( 4 F) transitions of Cr 3+ 26,34,41 with the 2 G 11/2 ‐, 2 H 9/2 ‐, 2 F 7/2 ‐, 2 H 11/2 ‐, 4 S 3/2 ‐, 4 F 9/2 ‐ → 4 I 15/2 transitions of Er 3+ 33,34,41 …”

“…Moreover, the green UC emission intensity of Er 3+ /Cr 3+ /Yb 3+ tri‐doped was substantially enhanced. This suggests the potent combination and ET process between Er 3+ and Cr 3+ 33,41 …”

“…The CIE 1931 (x; y) chromaticity coordinates of these UC emissions were identified in the yellowish‐green color region 42 . With increasing concentration of Cr 3+ from 0 up to 5 mol.%, the CIE 1931 (x; y) chromaticity coordinates for the UC emission of Er 3+ /Cr 3+ /Yb 3+ tri‐doped gradually moved 34,41,42 and were eventually located in the central position of the yellowish‐green color region 42 . Figure 6(C) suggests that the simultaneous increasing intensity of the green UC emission and decreasing intensity of the red UC emission of Er 3+ /Cr 3+ /Yb 3+ tri‐doped have contributed to this movement.…”

“…The absorption spectrum of Cr 3+ /Yb 3+ co‐doped is shown by the green curve (c) of Figure 2. The absorption spectrum of Cr 3+ expresses two distinct peaks at ~440 and 638 nm, corresponding to the 4 A 2g → 4 T 1g ( 4 F), and 4 A 2g → 4 T 2g ( 4 F) transitions of Cr 3+ 25‐27,35,41 …”

Optimization of the Synthesis and Energy Transfer of Ca2MgWO6:Cr3+,Nd3+

“…Xu et al studied CMW:Cr 3+ and CMW:Cr 3+ ,Yb 3+ . It turned out that Cr 3+ in this host material can be very efficiently excited in the ultraviolet range [17,18].…”