Sketch the potential energy or EC and EV as a function of position in a semiconductor crystal which contains
(a) a complete random distribution of a small fraction of the host atoms from their lattice sites,
(b) non-crystalline or amorphous regions where the host atoms are completely randomly located,
(c) donor impurity atoms located on a superlattice,
(d) substiitutional donor impurity atoms completely randomly distributed,
(e) substitutional donor impurity atoms not as randomly distributed as in problem (d),
(f) donor-acceptor impurity pairs whose separation in completely randomly distributed.