Journal of Luminescence 40&41 (1988) 661—662 North-Holland, Amsterdam
3~SENSITIZED, Tb3~, Mn2~COIJOPED POLYALUMINATE PHOSPHOR
Guangyan HONG, Qienxin JIA and Younj LI Changchun Institute
of Applied Chemistry, Academia Sinica,
The idea of using oI~e± sensitizer with two “cooperative” activator has been carrierd out in a Ce3+ sensitized, Tb , Mn codoped polyaluminate. The phosphor emits strong green light and may be used as a competitive component of tricolor phosphor for fluorescent lamp. For improving the light output of a phosphor, people have made many efforts hosts,
in developing new
use of doping
uaually in the sensiti-
zation case one activator is used with one sensitizer. On the bases of the work on the luminescence
of the activator is needed for example in some Ce—Tb
proposed an alternate
means i.e. to use one sensitizer with two “co— operative” activators; one of them emits in a broad band with peak near the region of sensi— -
In concrete, this 3~ idea has been carried out in a Ce sensitized, 3+ 2+ Tb , Mn codoped polyaluminate. The phosphor
FIGURE 1 3+ Spectra of Ce The excitation
respond of human eye.
thus prepared -
green light under
UV excitation and may be used as a competitive component of tricolor phosphor for fluorescent
302, 319, 340, emission peaks
350, 368, 379 and 485nm. The situate at 490, 541, 585 and 5 7 625nm, corresponding to the B —— F. transition 4 j ig. )~
lamp. Ce3+ sensitized Tb3-i- , Mn 2+ codoped poly— aluminates were prepared by a solid state reac-
2O3, MgO, CeO2, Tb407, MnCO3 in the calculated amount and a certain amount of flux were mixed and fired at 1300°C for 2 hrs
a reducing atmosphere. The structure
of the products
x—ray diffraction to be hexagonal. In this peak locates at host 28mm,theandexcitation the emission
3+ of peakCe at -
348nm. Both of them are broad bands (Fig. 1). 0022—2313/88/503.50 © Elsevier Science Publishers By. (North-Holland Physics Publishing Division)
FIGURE 2 3+ Spectra of Tb
G. Hong et a!.
codoped / Ce3~sensitized, Th3~,Mn2~
FIGURE 3 Spectra of Mn2~
FIGj~E~‘ 3+ 2+ Emission spectra of Ce , Tb , Mn
The main excitation bands of Mn2+ locate at 280,
emission band peak
at 5lOnm (Fig.3),
just between the 490 and 541nm peaks of TbS+. In this host the sensitization of Ce3+ may
It seems to us that above proposal, work with tive”
phosphor in other systems
too, and furthermore
enhance the emission intensity of Tb3+ or Mn2+
it is probable to develop a phosphor which have
of them emit
peak positions. And a sample sensitized by Ce3+ codoped with Tb3+ and Mn 2+ when excited at 28mm
ciently in a given host.
Natural Science Foundation of China.
emission peaks corresponding tions of Tb
The project was supported
but at the same time 4— another broad
band emission peaking at 516nm originated from 2+ Mn also appears in the spectra; i.e. the exci— 3+ tation energy of Ce can be effectively and 3+ 2+ simutaneously transfer to Tb and Mn and their emission are compounded together, so that
1. J.M.P.J. Verstegen, J. Electrochem. Soc., 121 (1974) 1623. 2. Hong Guangyan, Li Youmo, Luminescence and
4. Hong Guanyan, Li Youmo, Yue Shuying, Inorga— nica Chimica Acata, 118, (1986) 81.
emission intensity .
increases (Fig.4). 2+ Mn the amount
It implies that by incorporating
of expensive Tb3+ needed may be reduced in preparing an efficient green light emitting phosphor.
Display Devices, Vol.5, -
No.2, (1984)82. -
3. Li Youmo, et al., Luminescence and Display Devices, Vol.2, No.1, (1981) 47.