The conductivity of a given material should somehow depend on the band gap energy and the refractive index. I know that the band gap energy is obtained from Tauc plot. But how one retrieves these info from that plot or others? If photons the medium travels at a less speed than c, then it must have acquired a mass. Is the photon emitted due to the electron transition between the valence and conduction bands is mass-less or massive? I should expect the emitted photons to be massive inside the material and lose their mass when come outside.
What is wavelength of the photon inside the material? Is it simply n lambda!!! Can we consider refraction as red/blue shift of light
How energy gap and refractive index are co-related, follow this article
Energy gap–refractive index relations in semiconductors – An overview
Infrared Physics & Technology 50 (2007) 21–29
Dear Srkar,
Thanks but I trust it should also depend on the wavelength.
You did start by saying "of a given material"...It depends on the material. Semiconductors such as silicon might be different than insulators. If you're looking for an insight into the whole problem, start by working your way into the alkali halides because there's a great deal of excellent data on the band gap and the refractive index on them. Furthermore, if you'd really like to learn something plot up the data because you could be in store for some surprises.
Dann Passoja