What is the operating principle of a semiconductor device?
A1 When a P-type semiconductor and an N-type semiconductor are bound, the bound portion becomes a stable area called a depletion layer. If a battery is connected, with the positive pole to the P-type side and negative pole to the N-type side of these joined semiconductors, the depletion layer narrows, carriers can move between the two semiconductors and current can flow between them. Conversely, if the negative pole of the battery is connected to the P-type side and the positive side to the N-type side, the depletion layer widens, and carriers can no longer move between the two semiconductors, and consequently, no current can flow. This is rectification and the operating principle of a diode. The name diode means di-electrodes (two electrodes). The difference in the electrostatic potential between the top and bottom of the depletion layer is known as the diffusion potential. When forward-bias (voltage that drops in the forward direction) that exceeds the diffusion potential minus the e
