Factors Affecting Phosphor Efficiencies Brightness

Let us now examine the factors which affect phosphor efficiencies. As we have said, the presence of an emission band implies an assembly of emitters (or excited states) having various energy states just prior to emission, as illustrated in the following  

We can conclude that the probability of emission, at time t, will be related to the overall half-life, TExcitation. of the excited state, namely- 

According to the Binomial theorem (considering that we have either 

We can illustrate this using a potential diagram similar to that given before, namely  

Eg is an activation energy for cross-over (relaxation and dissipation of energy to the lattice) from excited to ground state. It is easy to show that energy transferred from the excited state to the lattice has a certain probability. Pi, to occur, namely- 

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