Yan Kuo, Duan Changkui, Ma Yi, Xia Shangda. DISCUSSION ON THE MECHANISM OF PHOTOLUMINESCENCE OF NANOCRYSTAL ZnS:Mn<sup>2+</sup>[J]. Chinese Journal of Luminescence, 1998,19(1): 8-13
Yan Kuo, Duan Changkui, Ma Yi, Xia Shangda. DISCUSSION ON THE MECHANISM OF PHOTOLUMINESCENCE OF NANOCRYSTAL ZnS:Mn<sup>2+</sup>[J]. Chinese Journal of Luminescence, 1998,19(1): 8-13DOI:
DISCUSSION ON THE MECHANISM OF PHOTOLUMINESCENCE OF NANOCRYSTAL ZnS:Mn2+
It's beyond common understanding that the luminescent lifetime of
4
T
1
6
A
1
transition of Mn
2+
doped ZnS decrease drastically by 5 orders of maganitude from bulk to nanacrystal because the magnetic interactions which usuall relax the spin forbiddenness can not be so strong.In this paper
we present a possible mechanism involving in the exchange coulomb interaction between the d electrons of Mn
2+
and electrons of host.Assuming that the spin of the ground state of host is not zero
and that the exchange coulomb interaction cause mixing between the excited
4
T
1
state of Mn
2+
and certain excited state of host whose energy is slightly higher than
4
T
1
state of Mn
2+
we found that the spin-forbidden transition could be almost allowed.Morever
the mixing degree increases as the grain size of host decreases.A rough numerical estimation about this mechanism agrees with the results of experiment.