Key chemical parameters related to the width of the charge transfer band and the emission intensity of 5D0→7F2 in Eu3+ doped Ln2O3

Structural phase transitions and photoluminescence properties of Eu3+ doped Ca(2−x)BaxLaNbO6 phosphors

“…A broad band absorption peak in the range of 200-350 nm with a peak maximum at about 305 nm is mainly related to the charge transfer (CT) transitions of ligand O 2− atoms to Eu 3+ since the position of the O 2− → Eu 3+ charge transfer band (CTB) is usually located in the range of 170-260 nm in most hosts. [18][19][20] It is clear that all of the PLE spectra have a similar shape when monitored at 596 nm (Fig. 7a, c and e) and 618 nm (Fig.…”

Crystal structure and two types of Eu3+-centered emission in Eu3+ doped Ca2V2O7

“…Q μ B stands for the presented charge of the nearest anion in the chemical bond, and α μ b is the polarizability of the chemical bond volume in the μ type of chemical bonds. Also, the relationship between the environmental factor (h e ) and the environmental factor of any individual bond between the central atom and their nearest coordination atom (h e i ) can be expressed by [20,21] h 2 e ¼…”

“…Generally, the emission intensity of 5 D 0 -7 F 2 of Eu 3 þ increases with increase in the distortion degree of Eu 3 þ sites [20]. Also the distortion degree of Ca1 and Ca2 can be calculated based on the calculated chemical bond parameters using the standard deviation of the four Ca-O environmental factors (σ h e i À Á ) [20,21]. σ h e i À Á can quantitatively express the distortion degree of Ca1O 7 or Ca2O 6 from that of an ideal polyhedron with the same environmental factor (h e i ) for every chemical bond.…”

“…So their symmetry and environment are quite different. Generally, the emission intensity of 5 D 0 -7 F 2 of Eu 3 þ increases with increase in the distortion degree of Eu 3 þ sites [20]. Also the distortion degree of Ca1 and Ca2 can be calculated based on the calculated chemical bond parameters using the standard deviation of the four Ca-O environmental factors (σ h e i À Á ) [20,21].…”

“…Q B i stands for the presented charge of the nearest anion in the chemical bond. Therefore, the standard deviation σ h e i À Á is [20,21] σ h e i…”