Thus, the valence band and conduction band are further separated from one another by an energy gap of 0.1eV.Īpart from the band gap, one of the primary difference between conductor, insulator and semiconductor is that the conductivity of semiconductor can be found to be between the conductivity of insulator and conductor.The circuit connection of PNP transistor with supply voltages is given below. Now, in semiconductors, the Fermi level can be seen to be situated between the valence band and conduction band. While in the case of insulators, the energy band gap is found to be extremely high,which can be given by Eg = 6eV. The valence band and conduction band in conductors is almost close to one another, thus its energy gap is Eg = 0. In fact, a wide forbidden gap (more than 5eV) can be found for insulators, while a narrow forbidden gap (about 1eV) for semiconductors and absolutely no forbidden gap in the case of conductors. What is the name of the level formed due to impurity atom … Īns: The primary difference between conductors, insulators and semiconductors is mainly on the basis of their relative width of the forbidden energy gaps found in the energy band structures.What is the order of the reverse saturation current ….In breakdown region, a Zener diode behaves as a ….For the given circuit of p-n junction diode ….Consider the junction diode as ideal ….A n−p−n transistor is connected to common emitter configuration ….Which of the following is a semiconductor ….In a semiconductor, the conductivity ….A p−n photodiode is made of a material with a band gap of 2eV …. A junction diode has a resistance of ….Parallel Combination of Resistance Experiment IV characteristic of Curve for P-N Junctionįind V Values of U Values in Concave Mirror Thus, the total current is I = I e + I h.Ĭheckout Important Handwritten Notes on Semiconductors:Ĭonvert given Galvanometer into Voltmeter These holes move towards a negative potential that generates hole current (I h) under an electric field.Moreover, the movement of the hole is basically the movement of the bound electrons.It rather moves independently like a conduction electron contributing to electron current (I e) under an applied electric field.Thus, the electron that has been released from site 1 is not involved in the movement of the hole.The hole will now move from site 1 to site 2. Now, let us consider an electron from site 2 jumps to that vacancy or hole created in site 1.At site 1, a vacancy is created there from where the electron releases itself.Let’s assume, there are two sites, site 1 and 2.Due to thermal energy, the electron after being excited breaks itself away from the bond generating a free electron.If “e” is the number of free electrons, “h” is the number of holes, “n” is the total number of atoms present in an intrinsic semiconductor then,Īnother interesting property of semiconductors is that the holes move too, like electrons. The number of holes is equal to the number of free electrons in an intrinsic semiconductor.In this way, the positive charge is transferred from one position to another.Then, this hole also becomes occupied by some free electron and so on. A free electron now occupies this hole due to which another hole is created.There is a vacancy created in the crystal lattice due to the ionization of the atoms and the position from where the electron dislodges creates a hole which has an equivalent positive charge.When the temperature of the semiconductor is increased, the electrons break free from their shells as they gain more thermal energy.Two examples of intrinsic semiconductors are Si and Ge.Īs you can see, both germanium and silicon have four electrons in their outermost shells.As per the energy band theory, the conductivity of an intrinsic semiconductor is going to be zero at ambient temperature.Some of the most used intrinsic semiconductors are Germanium and silicon.It has an equal number of holes and free electrons. Intrinsic semiconductor is pure in nature and is free of any impurities.Read More: NCERT Solutions Semiconductor ElectronicsĪn intrinsic semiconductor can be defined as a semiconductor which is exceedingly pure. The video below explains this: Semiconductors and Insulators Detailed Video Explanation: Small amounts of impurity is added in a pure conductor. If a chemical impurity is added to an intrinsic semiconductor, then it is called Extrinsic Semiconductor.ĭepending on the impurity, Extrinsic semiconductors can be classified into two types: n-type and p-type semiconductors. Intrinsic Semiconductors are conductors found in its pure form.
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