Unformatted text preview: interatomic distance. (20 points) Hint: use the solution for a 1 m  long atomic chain. 6 QuasiFermi levels for electrons and holes in the undoped injection active region of GaAs LED at room temperature is 30 and 2 meV above and below respective band edges. Calculate radiative recombination rate and lifetime of carriers. Electron and hole nonradiative recombination coefficients: A =1x10 8 s1 ; radiative recombination constant: B = 1.5x1010 cm 3 s1 ; electron and hole Auger recombination coefficients: C e = C h = 1.5x1031 cm 6 s1 . (20 points) 7. Calculate and plot a free exciton luminescence line (position and shape) in Si at 4 K and 20 K at low excitation intensity. (25 points) Hint: use exciton Rydberg and TA and TO phonon energies to find the positions of two exciton lines, and density of state and Maxwell distribution to find the shape....
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 Spring '11
 SergeOktyabrsky
 Energy, Photon, optical phonon energies, piezoelectric acoustic phonon, optical phonon energy, Auger recombination coefficients

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