i have deposited CZTS layers by using rf sputtering at different deposition temperatures. for each different layer i am getting different peak of raman shift. that is due to may be due to phonon confinement further related with particle size. as band gap is a function of particle size. if these are the facts, can i establish indirect relation between band gap and raman shift?
Possibly, but it may not be an easy job, I am afraid.
You will probably need to show that:
1. The bandgap of your CZTS films shifts in accordance with your Raman data;
2. The grain-size of your CZTS is small enough to exhibit confinements of electronic and vibrational states
3. The grain-size is the only variable in your CZTS films. In other words, there may be other changes when you grew films in different conditions (such as chemical compositions, presence of secondary phases, crystalline quality, incorporation of impurities, and level of disordering etc ...)
Raman peak may shift for various reasons. Alex Redinger at Luxembourg has published Raman studies of CZTS in the past. Also, you may be able to find some theoretical studies.
The above two replies correspond important points. I'd like to add two more:
1. Band-gap vs particle-size curve for quantum confinement is given by Brus equation. You may see, if the grains are small enough to confine electronic states using a Brus fit. For such a fit, you may visit this paper:
Article Size-modulation of functionalized Fe3O4: Nanoscopic customiz...
2. If it is not so, the Raman shift may not be linked to particle/grain/crystallite size and band-gap. Another reason of such shift is tensile/compressive stress that the molecules are subjected to. You might explore this side too...
- Badges
- Science topic