Arrange the following materials in ascending order of their diffusivity in Silicon.

(i) Li

(ii) Na

(iii) L

(iv) Ag

Question

Question

This question was previously asked in

UGC NET Paper 2: Electronic Science Dec 2018 Official Paper

Answer 1

Diffusion in semiconductors refers to the migration of atoms, including host, dopant, and impurities.

Diffusion describes the movement of atoms through space, primarily due to thermal motion, and it occurs in all forms of matter.

The mobility of an atom or defect in the crystal lattice is characterized by its diffusivity or diffusion coefficient, D.

Einstein equation gives the relationship between D and µ:

D/ µ = kT/ q

Diffusivity of miscellaneous impurity in silicon is given below:

So Ascending order of diffusivity will be:

Na < Ag < Li

(ii) < (iv) < (i)