Zener Effect

• Standard diodes (a form of semiconductor) operate on forward voltage, which cause the motion of current in only the forward direction, exploiting a positive/negative (p/n) junction between an anode (positive) and cathode (negative). The Zener Effect is based on reverse voltage, which causes the breakdown of the p/n junction, causing current to run in reverse. Zener diodes make use of this effect.
  
  

Energy Production

• In a standard diode, energy is produced when electrons fall into holes, which are defined as the absence of electrons. The amount of energy produced is based on the gap between electrons and holes. Ionization prevents the produced current from flowing in the opposite direction. In a Zener diode, when reverse voltage is applied, both holes and electrons are pulled away from the p/n junction, which causes a breakdown in current flow; the point at which a Zener diode's current breaks down is its Zener voltage. The ability for current to flow in the opposite direction limits damage by too much voltage applied to a standard diodes.
  
  

Applications

• Zener diodes are used to regulate voltage in circuits, holding the level of voltage within acceptable parameters for the system. Zener diodes can be used in regulators, comparators (devices which monitor and switch between two different voltages), and limiters, which split and control sinusoid waves (alternating current). Because of these properties, Zener diodes are common components of power supplies.