(Solved): For a 1cm^(3) intrinsic Germanium crystal, at 200 K the intrinsic carrier concentration is (10^(12)) ...
For a
1cm^(3)intrinsic Germanium crystal, at 200 K the intrinsic carrier concentration is
(10^(12))/(c)m^(3). At this temperature the electron mobility
\mu _(e)=8000(cm^(2))/(Vsec)and hole mobility
\mu _(h)=
5000(cm^(2))/( Vsec ). (a) (3 pt) If 100 V is applied across the Ge cube at 200 K , what is the current you measure? (b) (3 pt) What is the diffusion coefficient for electrons and holes? (c) (4 pt) What is the intrinsic carrier concentration of this crystal at 400 K ? (Assuming that the band gap of Ge at 200 K and 500 K is the same
=0.661eV). (d)
(5pt)It is known that the conduction band and valence band effective density of states at 300 K for Ge are
N_(C)=1.03\times 10^(19)cm^(-3)and
N_(V)=5\times 10^(18)cm^(-3), respectively. The Ge crystal is now doped with Ga with concentration of
6\times 10^(16)cm^(-3). From the following plot, find the electrical conductivity and the Fermi level with respect to the valence band maximum (in eV ). (e)
(5pt)The Ge is further doped with As to a concentration of
1\times 10^(17)cm^(-3). What is its conductivity and where is its Fermi level?
