Physics-432

Homework Set (7)

This homework set is due on Saturday (15^th of Safar) at 10.00 p.m.

If you need help, please e-mail me or visit me in my office.

Please solve fully and clearly, state assumptions, circle final answers, and comment wisely (when applicable).

You are free to discuss with your colleagues, but makes sure your solution is truly yours.

Question #1:

Describe, in k-space, how an electron in a crystal energy band moves.

Question #2:

In your own words, provide a physical interpretation of the "effective mass" of an electron in a crystal.

Question #3:

In class, we studied intrinsic semi-conductors. In a few qualitative statements, describe what happens to the properties of the semi-conductor when impurities are introduced.

Question #4:

e-mail me (zhyamani@kfupm.edu.sa) two web-site URLs that describe semi-conducting crystals and their properties.