What is the potential barrier of a silicon diode?

The potential barrier of a silicon diode is typically around 0.7 volts. This value represents the built-in potential difference that must be overcome for current to flow through the diode in the forward bias condition. When the silicon diode is forward-biased, a voltage of approximately 0.7 volts is required to sufficiently allow charge carriers (electrons and holes) to recombine and flow across the junction, thus enabling conduction.

In semiconductor physics, this barrier arises due to the differences in concentration of electrons and holes on either side of the p-n junction. At thermal equilibrium, a depletion region forms at the junction where the majority carriers from each side combine, resulting in a potential gradient. Upon applying external voltage, exceeding this potential barrier facilitates the movement of charge carriers and hence, conduction occurs.

This characteristic forward threshold voltage is distinct to silicon diodes, which is why 0.7V is commonly cited in educational materials and electronics references regarding diode operation.