GaAs is a typical semiconductor compound that has the zinc blende structure.
(a) Draw a cubic unit cell for the zinc blendc structure showing the positions of Ga and As atoms.
(b) Make a drawing showing the in-plane crystallographic directions and the positions of the atoms for the (11 1) lattice plane.
(c) Repeat for the (100) plane.
(d) Calculate the surface density of atoms in (100) plane.