Intrinsic semi-conductor is chemically pure and no doped using any impurities. It is a single metal piece either silicon or germanium. All intrinsic semiconductors are obeying solid metals energy bond diagram. In an intrinsic semiconductor free electrons are almost equal to no of holes. So it behaves as perfect insulator in absolute zero temperature 0°K (-273.15 °C). In increase of thermal energy due to thermal agitation number of holes generated in equal to number of holes generated. So it does not conduct electricity in changes of temperature also. Intrinsic semiconductors are also called as pure semiconductor and I-semiconductor.
Current conduction in an intrinsic semiconductor
The current conduction of intrinsic semiconductor as same as a normal conductor conducts its electricity. In below figure circuit diagram shown to study about it.
intrinsic semiconductor’s one end connected with positive end of the battery source. Another end connected with negative end of the battery source. When considerable voltage applied between two end of intrinsic semiconductor, free electrons, holes are drifts towards positive and negative terminal of battery source. While continues application of voltage it breaks covalent bod of valence electrons available in outermost orbit. So those electrons become free and switch to valance bond to conduction bond. As electron released from a particular atom it affected deficiency of electron, which becomes positive ion or holes. Hence continues generation of free electrons and holes, those continuously drifts towards opposite polarity of battery terminal.
In normal state electrons are roaming freely in random direction. But applying external electric field current flown due to drift of electrons towards negative terminal and holes towards positive terminal it is called as drift current.
Current flowing cause of drift of free electrons towards positive terminal called as electron current or electric current.
Current flowing due to drift of holes towards negative terminal called as hole current.
However conventional current known as it flowing positive terminal to negative terminal used for practical use.
Example of Intrinsic semiconductor
- Silicon
- Germanium
