2.5 Performing a literature search for the required constants, draw the room-temperature
thermal-equilibrium band diagrams for the following heterojunctions and calculate the
values of the built-in potential and the width of the depletion region. Indicate the sources
used in extracting the required constants:
a. Si-doped $Al_{0.3}Ga_{0.7}As$/undoped GaAs, while the dopant distribution is uniform with a
concentration equal to $10^{16} cm^{-3}$.
b. Si-doped GaAs/undoped $In_{0.2}Ga_{0.8}As$, while the dopant distribution is uniform with a
concentration equal to $10^{16} cm^{-3}$.
c. B-doped $Si_{0.8}Ge_{0.2}$/P-doped Ge, while both dopant distributions are uniform. Boron
concentration is equal to $10^{17} cm^{-3}$, and the phosphorus concentration is $10^{15} cm^{-3}$.
Assume all dopants activated and the interface to be ideal with no strain. Use Vegard's
law wherever needed.
