CSU ECE331 Homework #2 Page 1 of 2 2013 © Copyright by Kevin Lear. All rights reserved. v13.09 ECE331 Homework Assignment #2 Due at time and date specified on website or in class. Please indicate the amount of time you spend on each problem. Don’t forget to credit your sources, include units and to show your work. 60 total points + 5 extra credit points. 1. (6 points). Write out a section of the periodic table that contains the correct one or two-letter symbols for the following elements: aluminum, antimony, arsenic, boron, carbon, gallium, germanium, indium, nitrogen, phosphorus, silicon and tin. Draw a box around each element’s symbol, and inside each box, write down the number of valence electrons for that element. 2. (4 points). (a) If a small amount of arsenic impurities are incorporated into a crystal of otherwise pure silicon, write an inequality with two greater than signs ( > ) to show the relationship between the electron, hole, and intrinsic carrier concentrations. Repeat part (a) if a small amount of boron impurities are incorporated into an otherwise pure crystal of germanium. 3. (6 points) Write an algebraic expression for the resistance of a rectangular resistor of height H, length L, width W, electron concentration n, hole concentration p, electron mobility µn, hole mobility µp, when an electric field of E is applied across the length of it. 4. (8 points) Calculate the conductivity (?) of intrinsic silicon at (a) T=300K and (b) T=600K using material property values from the textbook in Section 2.1. Note that mobilities vary with temperature, but you can neglect this effect in your calculations. 5. (5 points extra credit) Using a computer, plot the conductivity of intrinsic silicon including the effect of temperature dependent mobility across the temperature range T=300K to 600K on a semi-log graph. Include your program or formulas. 6. (10 points) Research using online or library resources the conductivity of intrinsic silicon, copper and window glass…