Semiconductors

Just for fun, today i will be doing something which i am interested in, which is semiconductors.

Semiconductors are actually solid crystalline substances of electrical conductivity between that of a conductor and an insulator.

Let me share with you what I have read. Electrons in semiconductors can have energies only within certain bands (i.e. ranges of levels of energy) between the energy of the ground state, corresponding to electrons tightly bound to the atomic nuclei of the material, and the free electron energy, which is the energy required for an electron to escape entirely from the material. The energy bands each correspond to a large number of discrete quantum states of the electrons, and most of the states with low energy (closer to the nucleus) are full, up to a particular band called the valence band. The ease with which electrons in a semiconductor can move from the valence band to the conduction band depends on the band gap.

Temperature affects the ease with which electrons move, which is why, the higher the temperature, the better the conductivity of a semiconductor.