Electronic Structure of Amorphous and Crystalline Germanium: Photoemission and Optical Studies

摘要

Photoemission has been measured in the 1.8 - 11.8 eV spectral range for cleaved single crystal Ge and amorphous Ge films. Cesium was used to lower the photoelectric threshold and extend the measurements for photon energies less than 5 eV for both phases. Similar measurements were made in the 5 - 11.8 eV spectral range on films grown at room temperature (i.e., amorphous films) and then annealed at temperatures below and above the amorphous-crystalline transition temperature. The optical properties for amorphous films have been determined in the 0.1 - 25.0 eV spectral range from a Kramers-Kronig analysis of reflectance data and in the infrared and absorption edge region for films grown on substrates held at temperatures just below the amorphous-crystalline transition temperature. (Author)