ECE 440 Homework VI Spring 2006 Due: Monday, February 20, 2006 1. (a) An n-type Si sample with N d = 1x10 17 /cm 3 is steadily illuminated such that g op = 3x10 21 EHP/cm 3-s. If τ n = τ p =1 μs for the excitation, calculate the separation in the quasi-Fermi levels, (F n-F p ). Draw a band diagram such as Fig. 4-11. (b) At t=0, the illumination in part (a) is terminated. Assuming the carrier lifetimes remain the same, calculate the separation in the quasi-Fermi levels at t=4 μs. Draw a corresponding band diagram at 300 K. 2. Refer to problem 1 part (a) in HW V. The same silicon bar is steadily illuminated at 300 K and a uniform excess carriers are generated in the Si bar. Assume that
This is the end of the preview.
access the rest of the document.
hole concentration, band diagram, diffusion current densities, n-type Si sample