Carrier Lifetime in Semiconductor: As already explained, in an extrinsic semiconductor the number of holes is equal to the number of free electrons. Due to thermal agitation, new electron-hole pairs are continually generated while other…
Fermi Level in Extrinsic Semiconductor: The equation for f(E) specifying the fraction of all states at energy E (electron volts) occupied under conditions of thermal equilibrium is called the Fermi-Dirac probability function and is given…
Carrier Concentration in Intrinsic Semiconductor: For determination of the conductivity of a semiconductor, it is essential to know the Carrier Concentration in Intrinsic Semiconductor of free electrons in conduction band and concentration of holes in…
Explain Conduction in Intrinsic Semiconductors: Explain Conduction in Intrinsic Semiconductors - As already explained, conduction through a semiconductor is due to two mechanisms viz. drift and diffusion. The movement of charge carriers (electrons and holes)…
Explain Conductivity of Metals: Conductivity of Metals - Consider a conductor of length l metres and cross-sectional area A square metres, as shown in Fig. 6.27. Let the number of free electrons available per m3…
Relaxation Time, Collision Time and Mean Free Path: The relaxation time is closely related to the mean time of flight between collision and also to the mean free path of the conduction electrons, which is…
Charge Densities in Extrinsic Semiconductor: Charge Densities in Extrinsic Semiconductor - Equation (6.19) provides relationship between the electron and hole concentrations n and p respectively. If ND is the concentration of donor atoms, there will…
Mass Action Law in Semiconductor: As already mentioned, concentration of free electrons and holes is always equal in an intrinsic semiconductor. When N-type impurity is added to an intrinsic semiconductor, the concentration of free electrons…
What is Extrinsic Semiconductor? Intrinsic (or pure) semiconductor by itself is of little significance as it has little current conduction capability at ordinary room temperature. However, the electrical conductivity of intrinsic semiconductor can be increased…
What is Intrinsic Semiconductor? An intrinsic semiconductor is one which is made of the semiconductor material in its extremely pure form. A semiconductor is not truly intrinsic unless its impurity content is less than one…
