## Explain temperature dependency in semiconductors, Electrical Engineering

Assignment Help:

Explain temperature dependence of electrical resistivity and conductivity in semiconductors.

The electrical conductivity of the semiconductors changes considerably with temperature changes. At absolute zero, this behaves as an insulator. And at room temperature, due to thermal energy, several of the covalent bonds of the semiconductor break. The breaking of bonds sets those electrons free that are engaged in the formation of such bonds. It results in few free electrons. All these electrons constitute a small current if potential is applied across the semiconductor crystal. It demonstrates the conductivity for intrinsic semiconductor increases along with increase in temperature as specified by η=A exp(-Eg/2kT), here η is the carrier concentration, T is the temperature, Eg is the energy band gap and A is constant. If in extrinsic semiconductors, addition of small amount of impurities creates a large number of charge carriers. That number is so large that the conductivity of an extrinsic semiconductor is a lot of times more than an intrinsic semiconductor at the room temperature. In n-type semiconductor each donor has donated their free electrons at room temperature. The additional thermal energy only serves to raise the thermally generated carriers. It increases the minority carrier concentration. A temperature is reached while the number of covalent bonds which are broken is so large which the number of holes is almost equal to the number of electrons. After that the extrinsic semiconductor behaves as intrinsic semiconductor.

#### Determine the value of rl, Q For the circuit of Figure: (a) Find an...

Q For the circuit of Figure: (a) Find an expression for the power absorbed by the load as a function of R . (b) Plot the power dissipated by the load as a function of th

#### Create a time diagram - conveyer, When the PLC is in the RUN mode it will s...

When the PLC is in the RUN mode it will switch ON the conveyer so it will run continuously. This project is divided into four outcomes: (a)    Detect block on entry, close

#### Why fet is a voltage sensitive device, Q. Why FET is a voltage sensitive de...

Q. Why FET is a voltage sensitive device explain from the drain characteristics? The JFET consists of a thin layer of n-type material with two ohmic contacts,the source S and t

#### Electro magnetics and transmission lines, how does the kb come across the s...

how does the kb come across the sheet charge in the amperian sheet?

#### Antenna fundamentals, Antenna Fundamentals We shall discuss here only t...

Antenna Fundamentals We shall discuss here only the fundamental concepts needed to understand the role of an antenna as a power-coupling element of a system. Figure illustrates

#### Principal of bipolar junction transistor, Principal of Bipolar junction tra...

Principal of Bipolar junction transistor: A bipolar junction transistor (BJT) is a three-terminal electronic device that constructed of doped semiconductor material and might

#### Connection of shunt capacitors - across individual customers, Connection of...

Connection of Shunt Capacitors - Across Individual Customers The most appropriate manner of improving PF of the distribution system and thereby reducing line losses is to link

#### State fleming''s right-hand rule, Fleming's Right-hand rule states: Let ...

Fleming's Right-hand rule states: Let the thumb, first finger and second finger of the right hand be extended such that they are all at right angles to every other. If the first

#### Find the magnetic-field force exerted on the moving bar, Consider the arran...

Consider the arrangement shown in Figure. A conductor bar of length l is free to move along a pair of conducting rails. The bar is driven by an external force at a constant velocit

#### Controls and system, transfer function of Lube Oil Cooler Temperature

transfer function of Lube Oil Cooler Temperature