In almost all electronic circuits, the semiconductor diode to use it in many of the circuit plays an important role, it is the birth of one of the earliest semiconductor devices and their applications are very wide.

The working principle of diode

Crystal diode for a p-type semiconductor and n-type semiconductor formation of the pn junction, in its interface on both sides of a space-charge layer, and has a self-built electric field. When there is no applied voltage, as pn junction on both sides of carrier concentration caused by the proliferation of poor self-built electric current and drift arising from the current equivalent and the balance of power in the state.

When the outside world a positive bias voltage, electric and outside the field of mutual self-suppression role of the Consumers carrier increase from the current spread of the forward current.

When the outside world a reverse bias voltage, external electric field and to further strengthen self-built electric field, in a certain form of reverse voltage and reverse bias voltage value unrelated to reverse saturated current I0.

When the reverse voltage applied to a certain high level, pn junction in the space charge of the electric field strength to achieve the critical values of the double-carrier process, a large amount of electronic hole right, had a great numerical breakdown of the reverse current, Breakdown phenomenon known as diodes.