Question

At T = 300 K, the hole mobility of a semiconductor μ_p = 500 cm²/V-s and \(\frac{{kT}}{q} = 26\;mV\). The hole diffusion constant D_p in cm²/s is _______

Answer 1

Concept:

The mobility of a carrier is related to the diffusion coefficient through Einstein’s relation as:

\(\frac{{{{\rm{D}}_p}}}{{{\mu _p}}} = \frac{{KT}}{q}\) 

D_p = Hole diffusion density

μ_p = Mobility of holes

Calculation:

With μ_p = 500 cm² / V-S and \(\frac{{KT}}{q} = 26\;mV,\) we can write:

\(\frac{{{D_p}}}{{500}} = 26\;m\) 

D_p = 500 × 26 m

D_p = 13000 m cm² / s

D_p = 13 cm² / s