The importance of the Stokes shift is not only a practical one, but it can also give you insight on what happens to the fluorescing system in the excited state. Small stokes shift means small geometrical relaxation and small solvation effects once the chromophore is excited. Large stokes shift means large geometrical relaxation and/or solvation effects.
The importance of the Stokes shift is not only a practical one, but it can also give you insight on what happens to the fluorescing system in the excited state. Small stokes shift means small geometrical relaxation and small solvation effects once the chromophore is excited. Large stokes shift means large geometrical relaxation and/or solvation effects.
I think it would be more appropriate to measure the shift between the peak of excitation spectrum of that particular emission. Absorption spectrum may refer to the excitation of more than one emission peak.
You must to give definition of PL. What is PL??? May be it is interesting for You publication from Russia (in English): V. E. Ogluzdin. UFN {bf \ 176} 415 (2006).
To measure the Stokes shift you may first get the photoluminescence spectrum. Then you calculate the energy E1 corresponding to the maximum of the spectrum. Next you fix the registration wavelength L1 at the spectrum maximum and start to change the excitation wavelength in a certain region (measuring excitation spectrum) looking for the excitation wavelength L2 providing maximum luminescence at the registration wavelength you have fixed. Next you calculate the energy E2 corresponding to L2 wavelength. The difference E2 – E1 will show you the Stokes shift.
To understand nature and quantity of Stokes or antiStokes shifts of the photoluminecsence (PL), it is necessery to know lines of absorptions of media, and to produce calculations in compliance with law conservation of energy.
To understand nature and quantity of Stokes or antiStokes shifts of the photoluminecsence (PL), it is necessery to know lines of absorptions of media, and to produce calculations in compliance with law conservation of energy.