Radiometric Measurements on Ag/n-Si Composite Films for Detecting Radiation in the Earth's Atmospheric Windows

摘要

The objectives of the research proposed in this 10-month effort were to assemble optical absorption and radiometric facilities for measuring the properties of Ag/n-Si composite films that are to be used as infrared detectors in the earth's atmospheric windows (1-2, 3-5, and 8-12 microns) from room temperature down to liquid nitrogen temperature and to begin making these measurements on films with specific microstructures. All of the equipment requested in the original proposal is now in place and measurements of the optical properties using the FTIR equipment have replicated data taken at the Johns Hopkins University Applied Physics Laboratories. Measurements of the radiometric properties have not yet begun. The delay in getting this equipment was a combination of manufacturers' delivery times after receipt of order and university delays in processing purchase orders. In addition to the above described work, the authors have developed a theory for the internal quantum efficiency of these films that use only experimentally determined quantities. This theory indicated that for applied electric fields on the order of 10+e6 volts/cm this efficiency at room temperature can be as high as 35% depending on the incident wavelength, providing a strong justification for pursuing the research being undertaken.