A natural semiconductor is one which is made of the semiconductor material in its extremely unadulterated structure.
Design of a diode
Semiconductor are materials whose electrical conductivity is lower than that of a conduit and higher than that of an encasing. At room temperature are electrons in a semiconductor have less energy to bounce from the valence band to the conduction band. at the point when enough energy is granted through warmth or other outer elements the electrons leap to the conduction band and it begins directing power.
Germanium and silicon are the most noticeable materials utilized in assembling semiconductors. Both the component have four electrons in its furthest orbital. These electrons structure covalent bonds with the four adjoining molecules and consequently it frames a tight gem grid without having free electrons power. at the point when enough energy is granted to the electron, it breaks the covalent bond and makes an opening. such a mix is known as an electron opening pair. The adjoining electron currently recreates the messed up covalent bond. Subsequently the opening whice is prior made disappears and another opening is shaped. Thus the development of openings will be toward the path inverse to that of an electron. Subsequently the opening addresses a positive charge. Openings likewise cause a current stream, however toward the path inverse to that an electron.
Types of Semiconductor
In view of the component utilized for doping the semiconductor can be grouped into a N-type semiconductor and a P-type semiconductor
at the point when silicon is doped with a penta-valent component like Phosphorous or Arsenic, a N-type semiconductor is framed. The Purpose of adding a penta-valent component is to build the electrical conductivity by expanding the quantity of transporter electrons . At the point when Arsenic is added, the four out of five electrons effectively structure covalent bonds with the adjoining molecules; yet the extra or the fifth electron is handily energized into the conduction band. At the point when the doping fixation is expanded, the quantity of such free electrons increments and this increases the conductivity. If one iota of the dopant is added to 10 million iotas of the semiconductor ( Si or Ge ) the conductivity builds multiple times. The electrons are the dominant part current transporters; since Arsenic gives electrons, it is called as a contributor or a n-type contamination.
At the point when silicon is doped with a tri-valent component like boron or Aluminum, a P-type semiconductor is framed. Expansion of a tri-valent component will increment electrical conductivity because of the increment in the quantity of openings. At the point when Aluminum is added each Aluminum particle is one electron short to make covalent bonds. Consequently the dopant molecule acknowledges an electron from the adjoining iota’s electron to shape the fourth covalent bond. This outcome in the arrangement of an opening. As in the N-type semiconductor, the conductivity is corresponding to the measure of the dopant added. The just difference is that in a P-type semiconductor, the openings dwarf the electrons. Subsequently openings are the dominant part transporters and electrons are the minority transporters. Since Aluminum acknowledges electrons from the adjoining molecules, it is called as an acceptor or a p-type contamination.