Hot-electron transport in epitaxialCoSi2films

We present a calculation of the photoelectric quantum yield of Schottky diodes, taking into account the spatial distribution of photon absorption in the metal film. We also present measurements of the quantum yield of epitaxial ${\mathrm{CoSi}}_2$ diodes, with metal thicknesses varying from 25 Å up to 1000 Å. A comparison of our experimental data with the results of this model leads to the determination of the escape depth of the hot electrons in ${\mathrm{CoSi}}_2$. The escape depth was found to be around 90 Å at room temperature and 100 Å at 77 K for 0.75-eV incident-photon energy and to decrease slightly with photon energy. These results are discussed and interpreted in terms of electron-phonon and electron-electron interactions.