Basic Structure of PN Junction in Semiconductor: Most semiconductor devices employ one or more P-N junctions. The P-N junction is the control element for the performance of all semiconductor devices such as rectifiers, amplifiers, switching…
What is Hall Effect in Semiconductor?: When a specimen (metal or semiconductor) is placed in a transverse magnetic field and a direct current is passed through it, then an electric field is induced across its…
Continuity Equation in Semiconductor: The Continuity Equation in Semiconductor states a condition of dynamic equilibrium for the concentration of mobile carriers in any elementary volume of the semiconductor. In Fig. 6.21 we have seen that…
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…