NNSE 508 EM Home assignment # 4 Due: March 1, 20111. A region between the capacitor plates is filled by amorphous selenium with a dielectric constant of 6.0 and a concentration of 3.67x1028atoms/m3. (a) Estimate the polarizability of a selenium atom. (b) Estimate the local field at a selenium atom if the charge on the plates produces a field of 1500 V/m. (c) Estimate the dipole moment of a Se atom in the field of part b. (d) What would the dielectric constant be if the local field were the same as the macroscopic field.? 2. Equation describing energy levels in an infinitely deep potential well may be applied to a quantum well formed in a layer of one semiconductor material bound by the layers of a different semiconductor (heterostructure quantum well). What should be the thickness of the semiconductor layer to ensure that the difference between the ground (i.e. the lowest) energy level and the first excited level is equal to the thermal energy (kBT) at room temperature (T = 300 K)? Assume mn= 0.1 me.
This is the end of the preview.
access the rest of the document.