17. A slab of intrinsic GaAs, 3 cm long, 2 cm wide, and 0.3 cm thick is illuminated by a monochromatic light beam, at which frequency the absorption coefficient is 500 cm The intensity of the beam is 5 x 10 Wcm, and the sample is at room temperature. a) Calculate the photon flux incident on the slab. b) At what depth does the intensity decrease to 5% of its value at the surface? c) Calculate the number of electron-hole pairs created per second in the slab. (Assume that the beam entering is totally absorbed through fundamental transition.) d) Calculate the increase in the conductivity Ao due to the illumination. Take the recombination time to be 2 x 10 s. [Data: The dielectric constant of GaAs is 10.4].

17. A slab of intrinsic GaAs, 3 cm long, 2 cm wide, and 0.3 cm thick is illuminated by a monochromatic light beam, at which frequency the absorption coefficient is 500 cm The intensity of the beam is 5 x 10 Wcm, and the sample is at room temperature. a) Calculate the photon flux incident on the slab. b) At what depth does the intensity decrease to 5% of its value at the surface? c) Calculate the number of electron-hole pairs created per second in the slab. (Assume that the beam entering is totally absorbed through fundamental transition.) d) Calculate the increase in the conductivity Ao due to the illumination. Take the recombination time to be 2 x 10 s. [Data: The dielectric constant of GaAs is 10.4].

College Physics

1st Edition

ISBN:9781938168000

Author:Paul Peter Urone, Roger Hinrichs

Publisher:Paul Peter Urone, Roger Hinrichs

Chapter29: Introduction To Quantum Physics

Section: Chapter Questions

Problem 82PE: Integrated Concepts A laser with a power output of 2.00 mW at a wavelength of 400 nm is projected...

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