2. A pn junction diode has the doping profile sketched in the figure below. Make the

assumption that Xn>xo for all applied biases of interest (Xn follows the same definition as in

the lecture).

(a) What is the built-in voltage across the junction? Justify your answer.

(b) Invoking the depletion approximation, sketch the charge density p versus x inside the

diode.

(c) Obtain an analytical solution for the electric field, E(x), inside the depletion region.

ND-NA

Not

N₂2

Xo

-NA