The crystal diode is a p-n junction formed by a p-type semiconductor and an n-type semiconductor, and a space charge layer is formed on both sides of the interface, and a self-built electric field is built. When there is no applied voltage, the diffusion current caused by the difference in carrier concentration on both sides of the p-n junction is equal to the drift current caused by the self-built electric field and is in an electrical equilibrium state. When there is a forward voltage bias in the outside world, the mutual suppression of the external electric field and the self-built electric field increases the diffusion current of the carriers and causes the forward current. When there is a reverse voltage bias outside, the external electric field and the self-built electric field are further strengthened to form a reverse saturation current I0 that is independent of the reverse bias voltage value within a certain reverse voltage range.

 

Diode in English is diode. The positive and negative terminals of the diode, one end is called the anode and the other end is called the cathode. Current can only move from the anode to the cathode. A diode is a device composed of semiconductors. Semiconductors can flow current in either direction.

 

Diode working principle (forward conduction, reverse non-conduction) A crystal diode is a p-n junction formed by a p-type semiconductor and an n-type semiconductor. A space charge layer is formed on both sides of the interface, and a self-built electric field is built. When When there is no applied voltage, the diffusion current caused by the difference in carrier concentration on both sides of the p-n junction is equal to the drift current caused by the self-built electric field, and it is in an electrical equilibrium state. When a forward voltage bias is generated, the mutual suppression of the external electric field and the self-built electric field increases the diffusion current of carriers and causes forward current (that is, the reason for conduction). When a reverse voltage bias is generated, the external electric field and the self-built electric field are further strengthened, forming a reverse saturation current I0 independent of the reverse bias voltage value in a certain reverse voltage range (this is also the reason for non-conductivity). When the applied reverse voltage reaches a certain level, the electric field strength in the space charge layer of the p-n junction reaches a critical value, resulting in a multiplication process of carriers, resulting in a large number of electron-hole pairs and a large reverse breakdown current. , known as the breakdown phenomenon of the diode.