HOT ELECTRON SCATTERING AND PHOTOEMISSION MEASUREMENTS ON METAL-INSULATOR-METAL STRUCTURES.
Abstract
Internal photoemission studies on Al-Al2O3-Au thin-film structures have revealed a very asymmetric barrier structure, phi (Al-Al2O3) = 1.8 EV and phi (Au-Al2O3) = 4 EV. When this structure is irradiated by visible light, photocurrent flows only if the Au electrode is biased positively, that is, only the Al electrode emits photoelectrons; thus, quantitative calculations are possible. When the applied bias voltage is changed, the maximum of the barrier within the insulator shifts; this effect is used to analyze the energy of the photoelectrons within the insulating film. The photomeasurements are interpreted by assuming an electron-phonon scattering mechanism; scattering parameters are determined not only in the bulk of the sample but also in the region near the metal-insulator interface. This model was verified further by analyzing the emission of these photoelectrons into the vacuum, that is, the energy distribution is determined for those electrons that are photoelectrically excited within the Al electrode and then travel through the insulating layer and the top electrode. The modulated retarding-grid method and chopped-light technique employed are described. The electron-energy-distribution curves with wavelength and sample bias voltage as parameters are analyzed; these data are consistent with the internal photoemission results. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 01, 1968
- Accession Number
- AD0675555
Entities
People
- C. R. Young
- F. L. Schuermeyer
- J. M. Blasingame
Organizations
- Air Force Research Laboratory