(i) Explain the process of diffusion in semiconductor material. (ii) Explain Hall effect.
(i) Diffusion: In a semi conductor bar a concentration gradient exist when either number of electrons or holes is greater in one region of a semi conductor as compared to other region.
When such concentration gradient exist, the carriers (electrons/holes) move from the region of higher concentration to lower concentration this process is called as diffusion.
(ii) Hall Effect: If a piece of metal or semiconductor carrying current “I” is placed in a transverse magnetic field „B‟ then an electric field „E‟ is induced in the direction perpendicular to both I and B.
Hall effect is used to determine whether a semiconductor is N type or P type, and to find carrier concentration