3110018 Lecture Notes - Lecture 5: Intrinsic Semiconductor
27 May 2023
Department
Course
Professor
Page 1 of 3 V. A. Adhwaryu@ Physics Class
Intrinsic semiconductor
(i) CARRIER CONCENTRATION
At the temperature T (> 0 K), in a pure semiconductor the supplied
thermal energy ruptures bond (very little in number) ….
There will be formation of Electron and hole pairs….
…….. (i)
…………(ii)
o As per law of mass action#.
o It is trivial/ negligible since .
o It is valid for any semiconductor at the tie of equilibrium##
#-Specifically, it implies that for a chemical reaction mixture that is in equilibrium, the ratio
between the concentration of reactants and products is constant.
##-Thus, there are no net changes in the concentrations of the reactants and products.
*
}
}
}
}
}
}…(FINAL)
}= Intrinsic carrier concentration
From the above equation, At a given temperature….It is clear that the product of
does not , but remains constant.
The carrier concerntration in an intrinsics semi conductor is dependent only on the
Band Gap.
Finally, depends on temperature and the energy band gap (material).
