Charge
Capacitor
The phenomenon of conductivity in only one direction is used as an electrical current switching for rectification of half-wave, so, this is the most used diode effect in electronics, because allows the current to flow between its terminals in only one direction. This property is used in many electronic circuits (and rectifiers).
A rectifier is an electrical device that converts alternating current (AC), which periodically reverses direction, to direct current (DC), which flows in only one direction.
At some point, the potential formed by the pn junction don’t allow the electrons and gaps move.