Standard diode,electronic components, a device with two electrodes,it only allows current from a single direction flow, many applications use is the function of the rectifier. The varactor standard diode (Varicap Diode) adjustable capacitor is used as electronic.Most of the standard diode current direction we usually called "rectifier (Rectifying) function. The most common function of standard diode is only allowed current by the single direction (called forward bias), reverse blocking (called reverse bias). Therefore, the check valve can be thought of as an electronic version of the diode.
Vacuum electron diode early; it is a kind of electronic device capable of unidirectional conduction current.
A PN junction two lead terminals within the semiconductor diode, the electronic device according to the direction of the applied voltage, with conductivity of unidirectional current. Generally speaking, crystal diode is p-n interface of a p type semiconductor and N type semiconductor formed by sintering.It forms the interface of space charge layer on both sides,and forms a self built electric field. When the applied voltage is equal to zero, because the concentration of the p-n junction on both sides due to the difference of carrier diffusion current and built electric field caused by the drift current equal in power balance state, which is under normal diode characteristics.
The early diode contains "cat whisker crystal (" Cat's Whisker Crystals ") and vacuum tube (UK called" thermionic valves (Thermionic Valves) "). Today,most diodes are mostly used in semiconductor materials such as silicon or germanium.
The applied reverse voltage does not exceed a certain range, the current through the standard diode is the minority carrier drift which is caused by the movement of the reverse current. The reverse current is very small, the standard diode is in the off state. This is also known as reverse current reverse saturation current and leakage current,standard diode reverse saturation current temperature is greatly affected. Reverse current general silicon tube is much smaller than the Ge tube,small power silicon tube reverse saturation current at the level of NA, small power germanium tube in the muon A orders of magnitude. When the temperature rises, the semiconductor heating excitation, the increase in the number of minority carriers, reverse saturation current increases.