I have a few questions related to PL (images attached for same material by 2 methods), It would be great to get some help.
1. What is the physical meaning of highly intense PL? Does this mean that the material is highly crystalline?
2. When the intensity is high, does it mean that the electron-hole recombination is quick? If so which would be the targetted applications with this material?
3. Is there any significance of the area under the PL peaks? If yes, which peak (excitation or emission)?
4. It was seen that there was a switch in the intensity of emission peak on comparing both data. What is the significance of such an intensity switching?
5. Is PL the right technique to identify the bandgap? If yes, is it 1240/excitation wavelength?
6. If the materials emission spectra show a high intense peak at 686nm for an excitation wavelength of 227nm, is it necessary for the material should glow when short UV is given?
7. What could be the possible applications of materials exhibiting properties like this ?
It would be great if any experts can help me with the answers.
The diagrans looked like the emission spectra at two excitation wavelengths. you have only got Em spectrum, but not Ex spectrum. you could possibly obtain the emission peak at.higher intensity if ecited at other wavelength instead of those two. This can be clear about the maximum Em intensity after you have got Ex spectrum of this material.
Ex spectrum can be obtained by fixing the emission peak position whilst varying Ex wavelength from UV up to ~400nm. Em spectrum can be then obtained by fixing Ex wavelength at the max output Em peak whilst scanning Em wavelength.
Jp Wu, the first peak is the excitation spectra and the second is the emission. I have clubbed both in one graph. As you said, when I excited at 227nm I got the 686 nm emission and when I fixed the emission at 686 nm, I got 227nm excitation.
- Badges
- Science method
- Similar topics
- Methodology
- Absorption Spectroscopy