ECE 2212

PROBLEM SET 4

S. G. Burns

Due: 20 February 2013

1. Text 2.33 and Text 2.34. For both problems sketch the energy bands showing the location of the conduction band, valence band, and Fermi level. Use the material we discuss in class on Friday, 15 February.

2. A Si junction diode at 300^º K has N_A= 2 x 10¹⁸ cm^-3 and N_D= 4 x 10¹⁴ cm^-3 .

(a) Use the Solecon curves to find the resistivity, ρ, in each region.

(b) What is the mobility of the majority charge carriers in each region? Use Figure 2.8.

(c) Compute the junction potential V_J and provide values for the majority and minority carriers in each region.

3. A silicon diode at 27C has a reverse saturation current of I_S= 5 mA. At what applied voltage will I_D= 100 mA. Assume h=N=1.

4. Text 3.21 This is very similar to what you will be doing in lab on Thursday, 21 February. You can apply linear regression routines in your calculator to assist in this.

5. A silicon diode at 27°C has a reverse saturation current given by I_S = 5 mA. At what applied voltage will the current be 5 mA? Assume the non-ideality factor, h = 1. Demonstrate this analytically and with a SPICE plot of the I-V characteristic. You can modify the default diode SPICE model to do this curve fit. We will do the SPICE model on Monday, 18 February.. You might check out Appendix B in the text for some SPICE information. The equation y=mx + b, linear regression or least squares curve fit, provide “m” (the slope) and “b” (y-axis intercept)

In recognition of our study of some semiconductor physics or what physics majors call condensed matter physics.

And we don’t want to forget concepts learned in Physics 1

And now in “dishonor” of the University Active Directory (A/D) System which is a pain in the ….!!!