b The reverse saturation current is 1nA.
In a PN junction diode, the reverse saturation current is 10^-5 amps at 27^∘ C .
Note: We know that the current flowing in a reverse-biased PN junction diode is called the reverse saturation current. From the diode current equation I=Is(eVηVT−1) the current should decrease with increasing temperature but the opposite happens.
The maximum value of the photocurrent is called the saturation current. Saturation current implies that all photoelectrons emitted by the emitter are immediately collected by the anode.
The very small current that flows through the diode when the diode is in reverse bias is called the diode reverse current. The reverse saturation current of a germanium diode is on the order of microamps. While the reverse saturation current of a silicon diode is on the order of nanoamps.
The current generated in this way is called the reverse saturation current and is denoted by Io. The word saturation means that the reverse current cannot be increased by increasing the reverse bias voltage across the diode (Figure 1). But it increases with increasing temperature.
The reverse saturation current is the reverse current of an ideal pn junction and is limited by the diffusion of minority charge carriers from the neutral areas towards the space charge zone.
Reverse current in PN junction
When a p-n junction is switched across a battery such that its n-type region is connected to the positive power of the battery and the p-type region is connected to the negative power of the battery, the pn junction should be in the reverse direction.
The negative potential on the p-side attracts the holes and the positive potential on the n-side attracts the free electrons. This widens the depletion region and increases the barrier potential.
Definition of reverse current
: Flow of reverse direct current or reverse phase alternating current of normal current.
Knee voltage is the forward voltage at which the current flow through the PN junction of the diode increases rapidly. Knee voltage is commonly observed in zener diodes.
Reverse current is the current that flows in reverse bias when the diode is reverse biased is called reverse current. The reverse current is designed to be smaller than the forward current.
For solid state diodes, the peak reverse voltage or peak blocking voltage is the maximum voltage that a diode can withstand in reverse bias without breaking down or avalanching. If this voltage is exceeded, the diode can be destroyed.
Reverse biasing occurs when the p-side of the diode is connected to the negative voltage of the battery and the n-side is connected to the positive voltage of the battery. This causes the thickness of the depletion layer to increase. As a result, much less current can flow through the PN junction.