ECE3080_Homework8

# ECE3080_Homework8 - (c) Determine the required...

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ECE 3080A: Homework #8 Due Date: December 3, 2007 Page 1 of 1 G EORGIA I NSTITUTE OF T ECHNOLOGY S CHOOL OF E LECTRICAL AND C OMPUTER E NGINEERING ECE 3080A: Semiconductor Devices for Computer Engineering and Telecommunication Systems Fall Semester 2007, Homework #8 Homework Due Date: Monday, December 3, 2007 1. MOSFET Scaling: (30 points) Apply constant-field scaling to the ideal current voltage relations in both the saturation and non-saturation (linear/nonlinear) bias regions. (a) How does the drain current scale in each bias region? (b) How does the power consumption per device scale in each bias region? 2. Optoelectronics: Absorption Coefficient: (30 points) A sample of GaAs is 0.35 μm thick. The sample is illuminated with a light source with h ! = 2 eV. (a) Determine the absorption coefficient. (b) Determine the percentage of light that is absorbed in the sample.
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Unformatted text preview: (c) Determine the required semiconductor thickness so that 95% of the incident photons are absorbed. 3. Solar Cell: Optimal Load Resistor: (40 points) A long silicon pn junction solar cell with an area of 2 cm 2 has the following parameters: N D = 10 19 cm-3 , D p = 6 cm 2 /s, p0 = 5 10-7 s, N A = 3 10 16 cm-3 , D n = 18 cm 2 /s, n0 = 5 10-6 s Assume that excess carriers are uniformly generated in the solar cell and that the photo-current density is J L = 25 mA/cm 2 . Let T = 300 K. (a) Plot the I-V characteristic of the diode. (b) Determine the maximum power output of the solar cell. (c) Calculate the external load resistance that will produce the maximum power. (d) If the solar intensity is increased by a factor of 10, determine the maximum power output of the solar cell. By what factor has the power increased?...
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## This note was uploaded on 02/17/2010 for the course ECE 3025 taught by Professor Citrin during the Spring '08 term at Georgia Tech.

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