p–n diode
![Mesa diode structure (top) and planar diode structure with guard-ring (bottom).](/Images/godic/202501/14/Two_diode_structures0734.png")
![Nonideal p–n diode current-voltage characteristics.](/Images/godic/202501/14/Nonideal_diode_current-voltage_behavior0735.png")
![Band-bending diagram for p–n diode at zero applied voltage. The depletion region is shaded.](/Images/godic/202501/14/Pn-junction_zero_bias0735.png")
![Band-bending diagram for p–n diode in forward bias. Diffusion drives carriers across the junction.](/Images/godic/202501/14/Pn-junction_forward_bias0735.png")
This article provides a more detailed explanation of p–n diode behavior than that found in the articles p–n junction or diode.
A p–n diode is a type of semiconductor diode based upon the p–n junction. The diode conducts current in only one direction, and it is made by joining a p-type semiconducting layer to an n-type semiconducting layer. Semiconductor diodes have multiple uses including rectification of alternating current to direct current, detection of radio signals, emitting light and detecting light.