Diodes are basic discrete semiconductor devices with unidirectional conductivity, whose core characteristic is that they only allow current to flow from the anode to the cathode and block reverse current. Common types include rectifier diodes, Schottky diodes, Zener diodes, transient voltage suppressor (TVS) diodes, fast recovery diodes and light-emitting diodes (LEDs), which respectively perform functions such as rectification, high-speed switching, voltage regulation, overvoltage protection, high-frequency circuit operation and light-emitting display. They are widely used in all electronic fields including power management, consumer electronics, automotive electronics, industrial control and communication equipment.