Construction of Diode
We know that there are two types of semiconductor materials: Intrinsic and Extrinsic semiconductors. In intrinsic semiconductors, the number of electrons and hole concentration are equal at room temperature. In an extrinsic semiconductor, impurities are added to the semiconductor to increase the number of electrons or the number of holes. These impurities are pentavalent (Arsenic, Antimony, phosphorous) or tri-valent (boron, indium, aluminium).
A semiconductor diode has two layers. one layer is of p-type and the other is of n-type semiconductor.
- If we add trivalent impurities in a semiconductor (Silicon and germanium), a greater number of holes are present and it is a positive charge. therefore this type of layer is known as the p-type layer.
- If we add pentavalent impurities in semiconductors (silicon or germanium), due to excess electrons there is a negative charge. therefore this type of layer is known as the n-type layer.
Diode
A diode is an electronic device that conducts electricity only in one direction. It is a device which is widely used in modern-day electronics. In this article, we will learn about diodes, their properties, symbols, types and others in detail.