Can anyone tell me the typical paths of holes and electrons in an unbiased PN junction at equilibrium? In terms of diffusion currents, is that only holes (majority carriers in the the P-Type) traveling exclusively within the valence band and electrons (majority carriers in the N-type) traveling exclusively within the conduction band, both remaining in their respective 'lanes' even across the PN junction and both due to concentration of charges (the coulomb effect)? And in terms of drift currents in the opposite direction, is that minority carrier holes traveling exclusively in the valence band and electrons traveling exclusively in the conduction band with both traveling due to the charge imbalance created by the diffusion current?
Electronic – What are the typical paths of holes and electrons in an unbiased PN junction
bandelectronpn-junction
Best Answer
Yes that's correct, the drift current is due to minority carriers in distance from the depletion area smaller then their diffusion length being drift across the depletion area (due to the built in field created by the diffusion).
Here is a band diagram
Note that the drift current under reversed bias is negligible (if it has something with what you asked)