Physics for Electrical Engineers
Prof. B. Jalali EE2
Midterm Exam Thursday 7. 2013
1. Which of the following semiconductors are transparent, partially transparent, non-
transparent for visible light (A=0.4-0.7p.m): Si. GaAs, GaP, and GaN?
EE2 Problem Set#4
Question 1 (10 points): Given the mobility of electrons as 1200 cm2/V-s, determine the
resistivity of a n-type silicon with 1016 cm-3 donor atoms. If the electron effective mass is
0.26mo, calculate the average scattering time (mean free
EE2 Problem Set#3
Question 1 (5 points):
(a) If I have 5 electrons all at a potential of 1V, what is the total energy of the electrons
(b) What is the voltage change for an electron if temperature is increased by 100K?
Question 2 (10 points): Sup
EE2 Problem Set#6:
Question 1 (15 points): An abrupt Si p-n junction has NA=1018cm-3 on one side and
ND=5x1015cm-3 on the other.
(a) Calculate the Fermi level position at 300 K in the p and n regions.
(b) Draw an equilibrium band diagram for the junction
EE2 Problem Set#5
Assume that ni in silicon at room temperature is equal to 1010 cm-3
Question 1 (10 points): Calculate the widths of the space charge region, xn, xp, and xd in
an abrupt p-n junction under thermal equilibrium conditions with NA = 5 X 1016