# Volume Density of states (electrons)

1. Sep 29, 2015

### orangeincup

1. The problem statement, all variables and given/known data
a)Find the densities of states 0.08 eV above the conduction band edge and 0.08 eV below the valence band edge for germanium. Be careful with units and be sure to give the units for your answer.

b) Find the volume density of states (i.e. number of states per unit volume) with energies between the conduction band edge and 0.4 eV above the conduction band edge for germanium.

2. Relevant equations
1/(1+exp(e-ef/kt))

3. The attempt at a solution
a) So I found density of states in conduction band is meant to be 1.04*10^19, and in valence band it's meant to be 6.0*10^18.
above conduction band edge:
1.04*10^-19

holes=.044 ih
holes= .28 hh

Assuming it's 300k my solution would be

Nc*exp(.08/0.0259)=0.044
Nc=0.002000

Nv*exp(.08/0.0259)=0.28
Nv=0.0128

for b, I have two values so do I need an integral, or should I average between conduction band and .04?

2. Oct 4, 2015