A p-type and n-type semiconductor are connected to form a diode, which is a semiconductor device. A diode can be either forward-biased or reverse-biased. Forward Bias is the condition in which the positive terminal of the battery is connected to the P-type while the negative terminal is connected to the N-type.
A linear device is one that obeys the linearity properties listed below:
Input and output change by the same amount. Scaling or symmetry are two names for this feature. So, .
This is the same as applying each input separately when the two inputs are combined. Additivity is the name given to this property. So, .
A diode is not a linear device because it does not obey any properties in forward or reverse bias. While the graph for linear devices produces a straight curve, the of a diode in forward and reverse bias does not.