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Unformatted text preview: 10 9 m-1 . At which speed does the electron actually travel? (Hint: use Google for the definition of phase velocity.) 3. Consider the one-dimensional example discussed in the class, with the atoms 0.3nm apart. a. If an electric field E equal to 100 V/cm acts on the electrons for a time interval of 10-13 sec, what will be the change in the k value of the electron? b. What would it be as a percentage of /a? 4. Figure 1 shows the solar spectral irradiance area (unit: W/m 2 nm) vs. different wavelengths (unit: nm) of a solar cell made out of Silicon (assume Eg=1.24eV). Calculate the percentage of the sun’s power that will be absorbed into the solar cell. 0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0 2.2 Spectral irradiance, W/(m nm) 2 500 1000 1500 2000 Wavelength, nm Figure 1...
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This note was uploaded on 10/07/2011 for the course EE 2 taught by Professor Vis during the Spring '07 term at UCLA.
- Spring '07