Question

Suppose that the concentration of electrons in n-type Ge at room temperature decreases linearly from 5 x 10^16/cm^3 to zero over an interval of 2mm.
a) Calculate the diffusion current
b) What is the value of the electric field required to produce a drift current equal to the diffusion
current of part (a)? Use the average value of the concentration in determining the drift current.
c) Draw a diagram to show the direction of the field.

Answer 1

If x is distance (mm) and y is electron concentration, then
y = 5*10^16 - 2.5*10^16 x
or,
y = 2.5*10^16 (2-x)

Now you can answer the questions