Define: i) Knee voltage ii) Reverse saturation current
i) Knee voltage : The applied forward voltage, at which the PN junction starts conducting and current starts increasing exponentially is called knee voltage. It is 0.7V for Si and 0.3 for Ge diode.
ii) Reverse saturation current
The current produced due to minority carriers generated by thermal energy is known as reverse saturation current. (Io)
(OR)
The reverse saturation current is that part of the reverse current in a semiconductor diode caused by diffusion of minority carriers from the neutral regions to the depletion region.