Valence band electrons in semiconductor may jump to conduction band if appropriate energy is applied in form of (I found the point from Samares' answer in this link and it also makes sense):
- Thermal energy
- Photon energy
- Electric field
According to this link, "Red photons of light carry about 1.8 electron volts (eV) of energy, while each blue photon transmits about 3.1 eV.".
So, if I place a silicon solid (that has a Silicon-Silicon lattice with each Silicon sharing its valence electrons with 4 other Silicon) in a well lit room, then can I say that majority of the valence band electrons (that can) will jump to conduction band?
Given that from this link, Silicon has a band gap of 1.1eV, it seems to me that the able electrons would get promoted to conduction band in a well lit room (natural sunlight thru windows or an electrical lamp). This is because the minimum photon energy from visible light is more than the band gap.
My confusion comes from certain points
- The band gap mentioned above might be for one isolated atom and not for an atom in a lattice.
- If the point above is wrong and the band gap given is indeed for an atom in a lattice then is it for all 4 valence electrons? I am inclined to think that when one electron will jump, the band gap for other 3 may increase.
So, is it correct to say that in a well lit room we will have conduction band filled as much as possible with valence band electrons, even at a fixed temperature (temperature variance won't matter then)?