A semiconductor has an electron concentration of 8 * 1013 cm-3 and a hole concentration of 5 * 1012 - Physics - Semiconductor Electronics Materials Devices And Simple Circuits

Question

A semiconductor has an electron concentration of 8 *
1013 cm-3 and a hole concentration of 5 *
1012 cm-3 The electron mobility is 25000
cm2 V-1 sec-1 and the hole
mobility is 100 cm2 V-1 s-1
Then,
(a) the semiconductor is n-type
(b) the conductivity is 320 m mho
(c) Both (a) and (b)
(d) None of the above

Vaibhav Tiwari · Accepted Answer

Dear Student,

electron concentration=8×1013 cm-3hole concentration=5×1012 cm-3So as the electron concentration is much more than that of the hole concentration, so the semi conductor is n-type
Conductivity, σ=qnMn+pMpσ=1
6×10-198×1013×25000+5×1012×100σ=1
6×10-1920000×1014+5×1014σ=1
6×10-19×20005×1014σ=0 32008 mho/cm