Broad Emission spectra range has 360 nm to 530 nm in water and HEPS buffer,
When we used this compounds for cell imaging purpose we seen green color on the cell. we also observed the green florescent fiber in florescent microscopy (LEICA 2500 LED) Can any one explain me why this happen ?
Thank you very much.
It is possible to excite poly atomic molecule even by a single wavelength light. But the emission spectra (Fluorescence) will have a broad band due to deexcitation from excited electronic state to any of the vibrational states of allowed lower electronic state. For example transition from S1 state to S0 state.
The spectrum is not actually broad. This is quite standard for organic molecule. Please go though this site (https://omlc.org/spectra/PhotochemCAD/) to have a better knowledge about the spectra of organic molecules.
Dear Mr. KshtriyaThe,
Welcome!
absorption occurs from the top filled level in the conduction band to the empty levels in the conduction band. While the emission is because of transitions from the lowest occupied levels in the conduction band to any empty level with lower lying energy levels under this conduction minimum level. Accordingly, i would predict that there is many empty levels above the occupied valence edge. This is natural for the fine grained structures.
In summary the emission is from the minimum conduction band edge to many empty levels above the filled valence band edge.
Best wishes
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