ELE533 Bipolar Devices

ELE533 98 Final Question 3 Answer

Derive Einstein's relation,

Dn = Vtun

Answer

Assume

Jn = unqnE + qDn(dn/dx) = 0

Since     n = niEV/Vt

E = -(dV/dx) = -Vt(1/n)dn/dx

unqnE = -unqnVt(1/n)dn/dx = -qDn(dn/dx)

Dn = Vtun