Posts

Showing posts from April, 2023

An overview on PN junction diode

Image
  PN junction: Fig: PN junction open circuit  Fig: PN junction characteristics Open circuit PN-junction: Fig: open circuit PN junction Diffusion current component:  As we have holes as majority in P side and electrons in N side there is concentration gradient on both sides which leads to movement of mobile carriers from both sides towards the other leaving immobile charges at the edges of the P and N side respectively.  This movement of charges causes the current known diffusion current as the charges are being diffused. Depletion region/junction/barrier potential: As we see due to diffusion the mobile charges leave the immobile charges which means charges are being depleted off from their respective position forming a depletion region which is also known as space charge region. Drift current: The minority carriers of P and N side are swept towards the edge of depletion region with the help of electric fields from N type and P type. The holes from N type are swept to...