EE 2 HW 3 09Spring-PS3 - QN

EE 2 HW 3 09Spring-PS3 - QN - 17 1/cm 3 of Boron? How far...

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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 (in eV)? (b) What is the voltage change for an electron if temperature is increased by 100K? Question 2 (10 points): Suppose the energy of an electron is given by E ( k ) = 2.74 × 10 -37 k 2 Joules where k is given in units of meter -1 . Find the effective mass, and give the ratio of the effective mass to the ordinary mass of the electron. Question 3 (10 points): How far is the Fermi level from the valence band for silicon if the doping is 2x10
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Unformatted text preview: 17 1/cm 3 of Boron? How far is the Fermi level from the conduction band, assuming the bandgap of silicon is 1.1 eV? Question 4 (10 points): A Si sample is doped with 6 X 10 15 cm-3 donors and 2 X 10 15 cm-3 acceptors. Find the position of the Fermi level with respect to E i at 300 K. Question 5 (15 points): Solar cell problem: Fig 1 shows the solar spectral irradiance area (unit: W/m 2 nm) vs different wavelengths (unit: nm). Please calculate the percentage of the suns power that will be absorbed into the material with E G = 1.24eV)....
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This note was uploaded on 03/29/2011 for the course ELECTRICAL EE2 taught by Professor A during the Spring '09 term at UCLA.

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