Energy Band Theory || Classification of Semiconductors||EST130Basic electronics

Hi, today we are going to discuss energy band theory. What is energy band theory? Based on this energy band theory, we can classify materials. Materials can be classified as conductors, semiconductors and insulators. This is what we are going to discuss today. Let's see energy band theory. First, let's consider a single isolated atom. If we consider a single isolated atom, the electrons in it will have definite energy. But if we consider a solid, all the atoms in it will be close to each other. In this case, the energy levels will affect the electrons in the outermost orbit. The energy levels in the outermost orbit will be affected by the effect of the neighbouring atom. When two isolated atoms are close to each other, the electrons in the outermost orbit will interact with each other. Through this interaction, the electrons in the outermost orbit will experience an attractive force. Therefore, the energies of the electrons will not be the same. There are chances that the energy levels of the electrons in the outermost orbit will be more than the original energy level and less than the original energy level. In this way, we can say that the energy levels of the electrons in the outermost orbit will be different. Energy bands are used to group these different energy levels. If we consider a single isolated atom, the electrons in it will have definite energy. But if we consider a solid, all the atoms in it will be close to each other. In this way, the energy levels in the outermost orbit will be more than the original energy level and less than the original energy level. In this way, the energy levels of the electrons in the outermost orbit will be different. In this way, we can say that the energy levels of the electrons in the outermost orbit will be more than the original energy level and less than the original energy level. There are a number of energy bands in the case of electrons, but we consider three energy bands to understand the behavior of a solid. The best way to explain the difference in electrical conductivity between a solid and a band is to explain the difference in electrical conductivity between a solid and a band. The range of energies possessed by valence electrons is known as valence band. Valence electrons are not tightly held by nucleus and hence they can become free electrons. These free electrons are responsible for conduction and hence these electrons are known as conduction electrons. The range of energies possessed by conduction electrons is known as conduction band. The separation between conduction band and valence band energy level diagram is known as forbidden energy gap. The energy produced by the heat of room temperature is sufficient to lift the electron from valence band to conduction band. Insulator or non-conductors are tightly held inside the insulator. The electrical resistance of the insulator is high. Semiconductors are neither good conductors nor good insulators. Semiconductors work as insulators at low temperature. An important property of a semiconductor is that its resistance decreases with increase in temperature. Semiconductors work as insulators at low temperature. Intrinsic Semiconductor and Extrinsic Semiconductor Intrinsic Semiconductor is a semiconductor in extremely pure form. Valence electrons of silicon and germanium are 4. Extrinsic Semiconductor is a pure semiconductor. Doping is done at a rate such that only one atom of impurity is added per 10-6 to 10-10 semiconductor atoms. Doping is done at a rate such that only one atom of impurity is added per 10-10 to 10-10 semiconductor atoms. If pentavalent impurity is added, if pentavalent impurity is added,