Diode and its basic circuit

The free electron energy is called the valence band, and the covalent bond energy is called the conduction band. The energy difference between them is called the band gap Eg












v.




When a forward voltage is applied to the PN junction, the current changes from P to N, the space charge region narrows, and the current is carried by the majority. The diffusion of current carriers forms a
PN junction. When a reverse voltage is applied, the current changes from P to N, and the space charge region becomes wider. The current is formed by the drift of
minority carriers, so the current is small. Minority carriers are greatly affected by temperature.


VD applied voltage















At this time, the voltage is small, and the broken line model is used