A crystal diode is a p-n junction formed by a p-type semiconductor and an n-type semiconductor, with space charge layers formed on both sides of its interface and a self built electric field established. When there is no external voltage, the diffusion current caused by the difference in carrier concentration on both sides of the p-n junction and the drift current caused by the self built electric field are equal and in an electric equilibrium state. When there is a forward voltage bias from the outside, the mutual suppression effect of the external electric field and the self built electric field increases the diffusion current of carriers, causing a forward current. When there is a reverse voltage bias from the outside, the external electric field and the self built electric field are further strengthened, forming a reverse saturation current I0 that is independent of the reverse bias voltage value within a certain range of reverse voltage. Below, Bern will explain the working principle of the diode.

Working principle of diode

The working principle of the diode mentioned here is forward conduction and reverse non conduction. A crystal diode is a p-n junction formed by p-type and n-type semiconductors, with space charge layers formed on both sides of its interface and a self built electric field. When there is no external 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 electric equilibrium state. When a forward voltage bias is generated, the mutual suppression effect between the external electric field and the self built electric field increases the diffusion current of carriers, causing a forward current. 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 that is independent of the reverse bias voltage value within a certain range of reverse voltage. (This is the reason why it is non-conductive) A crystal diode is a p-n junction formed by p-type and n-type semiconductors, with space charge layers on both sides of its interface, and a self built electric field. When there is no external 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 electric equilibrium state. When there is a forward voltage bias from the outside, the mutual suppression effect of the external electric field and the self built electric field increases the diffusion current of carriers, causing a forward current.

When there is a reverse voltage bias from the outside, the external electric field and the self built electric field are further strengthened, forming a reverse saturation current I0 that is independent of the reverse bias voltage value within a certain range of reverse voltage.

When the applied reverse voltage reaches a certain level, the electric field strength in the p-n junction space charge layer reaches a critical value, causing a doubling process of charge carriers and generating a large number of electron hole pairs, resulting in a significant reverse breakdown current, known as the diode breakdown phenomenon.

Through the explanation of the working principle of diodes above, everyone has a preliminary understanding and recognition of the basic theoretical knowledge of diodes. In one sentence, a crystal diode is a p-n junction formed by p-type and n-type semiconductors, with space charge layers formed on both sides of its interface and a self built electric field.