Cathodo- and Photoluminescence in the Tb3+ Activated Garnets of Type Cd3−xCaxAl2Ge3O12

Abstract

The Cd garnet Cd3Al2Ge3O12 activated with Tb3+ is an efficient green emitting phosphor. Under cathode ray excitation its efficiency is about 75% of that of Y3Al5O12:Tb3+ (P 53); the corresponding value for UV excitation is about 70%. The high efficiency is ascribed to an energy transfer between defect centres of the host and the activator, considerably reduced with increasing Ca content in the series Cd3−xCaxAl2Ge3O12:Tb3+. The luminescence properties are studied as a function of the Cd/Ca ratio.

Cathodo- and Photoluminescence in Nd3+ and Tb3+ Activated Garnets of Type Cd3−xCaxGa2Ge3O12

“…Interestingly, in the corresponding A1 containing garnet system Cd, -,Ca,Al,Ge,O,, : Tby" + an effective energy transfer from defect centres of the host to the Tb3+ activator is working in CL as well for defect centres with an emission at about 430 nm. Contrary to the present series they are most abundant in that system for x = 0 [4], thus indicating that the Cd/Ca ratio is not the only factor that influences the defect structure of the garnet host.…”

“…An enhancement of the activator luminescence is recognized for systems with an energy transfer between the host lattice and the activator (e.g. Y,A1,0,,: Ce3+ [l, 21, Cd,-,Ca,Al,Ge,O,,: Mn2+ [3], Cd,-,Ca,Al,Ge,O,, :Tb3+ [4]). In this paper we study the energy transfer between defect centres of the host and activator ions for the system Cd,-,Ca,Ga,Ge,O,~ activated with Nd3+ and Tb3+.…”

Cathodo- and photoluminescence in the Mn2+ activated garnets of type Cd3−xCaxGa2Ge3O12

“…For the Ce3+ activated garnets like Y3Al,OI2 an energy transfer between lattice and activator has been already recognized [l, 21. The same holds for the systems Cd,Al,Ge3012 : Mn2+ [3] and Cd3A1,Ge,OI2 : Tb3+ [4], containing the strongly sell-activated host Cd,Al,Ge,O,,. In this paper we study the cathodoluminescence (CL) and photoluminescence (PL) properties of the pure host system Cd3-,CaxGa,Ge30,, and the energy transfer between defect centres of the host and the activator manganese.…”

Tuneable persistent luminescence of novel Mg3Y2Ge3O12 garnet

“…Two broad excitation peaks with maxima at 272 nm and 317 nm as well as several relatively weak and narrow peaks in the 350-390 nm range could be detected in the PLE spectra monitoring the 540 nm emission. The most intense excitation peak with a maximum at 272 nm is associated with 4f−5d transitions of Tb 3+ and has been detected in similar materials [45][46][47].…”