A semiconductor is placed in an electric fiel | vedclass

Name: Exam Paper Generator | JEE NEET Paper Generator | Vedclass
Brand: Vedclass
Rating: 5 (35 reviews)

Question

(B) In a semiconductor,the number density of charge carriers $(n)$ increases exponentially with an increase in temperature because more covalent bonds

Vedclass · Accepted Answer

$n$ will increase but $v$ will decrease.

Vedclass · Answer

(B) In a semiconductor,the number density of charge carriers $(n)$ increases exponentially with an increase in temperature because more covalent bonds break,generating more electron-hole pairs.However,the drift velocity $(v)$ is given by $v = \mu E$,where $\mu$ is the mobility and $E$ is the electric field.Mobility $\mu = \frac{e	au}{m}$,where $	au$ is the relaxation time.As temperature increases,the frequency of collisions between charge carriers and the lattice increases,which decreases the relaxation time $	au$.Consequently,the mobility $\mu$ and the drift velocity $v$ decrease as temperature increases.Therefore,$n$ increases and $v$ decreases.

$A$ semiconductor is placed in an electric field. Let the number density of charge carriers be $n$ and the average drift velocity be $v$. If the temperature is increased,then:

Similar Questions

If the ratio of electron and hole currents in a semiconductor is $\frac{7}{4}$ and the ratio of drift velocities of electrons and holes is $\frac{5}{4}$, then the ratio of concentrations of electrons and holes will be

$A$ crystal of intrinsic silicon at room temperature has a carrier concentration of $1.6 \times 10^{16} / m^3$. If the donor concentration level is $4.8 \times 10^{20} / m^3$, then the concentration of holes in the semiconductor is

When an $N-$type semiconductor is heated,what happens to the charge carriers?

The length of a germanium rod is $0.928 \ cm$ and its area of cross-section is $1 \ mm^2$. If for germanium $n_i = 2.5 \times 10^{19} \ m^{-3}$,$\mu_h = 0.15 \ m^2 V^{-1} s^{-1}$,and $\mu_e = 0.35 \ m^2 V^{-1} s^{-1}$,then the resistivity is:

$A$ semiconductor has electron and hole mobilities $\mu_{n}$ and $\mu_{p}$ respectively. If its intrinsic carrier density is $n_{i}$,what will be the value of hole concentration $p$ for which the conductivity will be minimum at a given temperature?

Vedclass Test Series

Exam Paper Generator

Online Exam Module