# hw3 - the donor levels of simple donors such as P As and Sb...

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ECE 440 Homework III Spring 2006 Due: Friday, February 03, 2006 1. (a) It was mentioned in Section 3.2 that the covalent bonding model gives false impression of the localization of carriers. As an illustration, calculate the radius of the electron orbit around the donor in Fig. 3-12c, assuming a ground state hydrogen-like orbit in Si. Compare with the Si lattice constant. Use m n * = 0.26 m o for Si. (b) Repeat part (a) for the radius of an electron orbiting around the donor in GaAs, assuming m n * = 0.067 m o for GaAs. Compare the radius with the GaAs lattice constant. (c) Refer to part (a) and estimate the donor binding energy for Si. Compare your results to
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Unformatted text preview: the donor levels of simple donors such as P, As and Sb as shown in Fig. 4-9 (page 119). 2. Refer to problem 3 in HW I. If each gold atom donates one electron to the gold matrix at room temperature, estimate the electron concentration of gold. Is gold a conductor? 3. Math exercise: plot the function f(x)=exp(4x) from x=0.01 to 2.0 in two graphs. One is on a linear scale and the other on semi-logarithmic scale. For the semi-logarithmic plot assume that the coordinate “x” takes the linear scale....
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## This note was uploaded on 12/01/2011 for the course ECE 340 taught by Professor Leburton during the Spring '11 term at University of Illinois, Urbana Champaign.

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