Electronic States of Mn2+-Activated Phosphors.

Abstract

The electronic states of Mn2+ are derived from excitation spectra for five green‐emitting phosphors: (i) MgGa2O4:normalMn , (ii) Zn2SiO4:normalMn , (iii) ZnAl2O4:normalMn , (iv) Zn2GeO4:normalMn , and (v) Li2ZnGe3O8:normalMn . Only MgGa2O4:normalMn is found to give a spectrum consistent with octahedral (or tetrahedral) symmetry of Mn2+; the other four phosphors show spectra typical of Mn2+ in symmetry lower than octahedral. Solution of the Tanabe‐Sugano energy matrices using the MgGa2O4:normalMn levels as input gave Racah parameters of B=624 cm−1 and C=3468 cm−1 .

A search for luminescence of the trivalent manganese ion in solid aluminates

“…The emission peaks at 509 nm with vlbronic sidebands at 520 and 530 nm. Undoubtly this corresponds to Mn 2+ luminescence as has been found earlier by Palumbo et al (7). Mn 2+ is situated at tetrahedrally coordinated Zn sites with a low crystal field strength, leading to emission with relatively short wavelength.…”

Synthesis and evaluation of a PVDF–PT3MA–Zn2SiO4:Mn hybrid polymeric composite for optical device applications

“…50 In this case, the zinc silicate host lattice absorbs energy and transfers charge efficiently to Mn ions. However, Mn 2+ ions can be directly excited in the wavelength range between 357 and 500 nm.…”

“…10,49 In particular, the 442 nm line (z2.81 eV) is resonant with the 4 T 2 ( 4 G) energy level. 50 From this level, the excited electrons can relax to the 4 T 1 ( 4 G) state through non-radiative processes and then radiatively decay to the ground state. Therefore, the 442 nm is appropriate and also resonant with the PT3MA absorption peak.…”

Luminescence Properties of Rare‐Earth‐Activated Gadolinium Fluoride (GdF3) and Oxyfluorides (GdOF)

“…Generally, Mn2+-activated phosphors are divided in two classes, those with green emission and those with orange-to-red emission [12]. I n both classes emission arises from the 4T,(4G) level, the energy of which depends strongly on the crystal field strength.…”