ELEG 621 Solid State Electronics II
Homework #2 - due Thursday, 19 September 2002

1. Design a sodium vapor lamp that emits light at l = 590 nm with a bulb temperature of 540 K. The Na wavelength from the vapor in the bulb must penetrate the glass, but the bulb must stay hot. It is more efficient if the longer wavelengths (i.e. heat ) are reflected back into the interior of the bulb. Assume that the bulb container has layers of transparent glass, with a semiconductive reflective coating. Design the required electron concentration for proper operation. Assume that the contribution to the permittivity of bound electrons is 1.

2. Design a coating for windows in a house that lets in sunlight (effective source temperature of 6000 K) with wavelengths in the range from 0.3 micron to 1.5 micron, as

described in class. The room temperature within the house is 300 K and the window coating of conducing glass should reflect the heat wavelengths back into the house. Design an

electron concentration to optimize the energy efficiency of the house.

3. Look up data for the plasma frequency of gold (Au). Use your favorite handbook or acquaint yourself with some from the library.

Homework assignments will appear on the web at:  http://www.ece.udel.edu/~kolodzey/courses/ELEG621F02.htm

Note: On each homework and report submission, give your name,
the due date, assignment number and the course.