CST5026: Semiconductor Physics and Devices (I) (2024)
Homework (1) (deadline: 18. March)
1. (10%) Determine the number of atoms per unit cell in a (a) face-centered cubic, (b)
body-centered cubic.
2. (10%) The lattice constant of a face-centered cubic lattice is 4.25 Å. Determine the (a)
effective number of atoms per unit cell and (b) volume density of atoms.
3. (10%) The lattice constant of a face-centered-cubic structure is 4.25 Å. Calculate the
surface density of atoms for a (a) (100) plane and (b) (110) plane.
4. (40%) The lattice constant of a simple cubic lattice is a0. (a) Sketch the following planes:
(i) (110), (ii) (111), (iii) (220), and (iv) (321). (b) Sketch the following directions: (i) [110],
(ii) [111], (iii) [220], and (iv) [321].
5. (30%) Consider a face-centered cubic lattice. Assume the atoms are hard spheres with
the surfaces of the nearest neighbors touching. Assume the effective radius of the atom is
2.37 Å. (a) Determine the volume density of atoms in the crystal. (b) Calculate the surface
density of atoms in the (110) plane. (c) Determine the distance between nearest (110)
planes.