We all know due to quantum confinement bandgap increases on nanoparticles (and is size dependent). However, recently we grow a oxide based nanoparticles, capped with a bio-molucule. Optical absorption shows red shift ie. for the bulk the bandgap is in range of 3.1 eV and our nanoparticles shows 2.5 eV. We repeated many times and got same results. We have checked for purity and phase. Could anyone answer it with possible explanation
Respected Ravi sir,
I came to know you have checked for purity and phase. Have you visualized your nano and bulk samples through high magnification SEM or TEM. what about the size and morphology Sir?
Bulk i am referring from standard value. The size of our nanoparticle is 15 nm with spherical shaped
Respected Sir,
There is no possibility of red shift on decreasing particle size in the nano range. here are some suggestions that i can guess
1) To follow the same protocol and measure the band gap of commercial oxide powder and then compare.
2) You can follow another method for band gap measurements. The procedure you followed may be a problem.
- Badges
- Science topic
- Similar topics
- Chemistry
- Nanotechnology
- Nanostructured Materials
- Nanoparticles