Hot-electron lifetimes in metals: A combined ab initio calculation and ballistic electron emission spectroscopy analysis

A first-principles analysis of ballistic electron emission spectroscopy (BEES) is used to extract hot-electron lifetimes in metals. The lifetimes are computed within an ab initio framework based on density-functional theory and the GW approximation, and are used in a Keldysh Green function approach for the calculation of BEES currents. For the two prototypical systems Au/Si and Pd/Si, which exhibit a significantly different scattering dynamics, we find an excellent agreement with experiment, which allows an accurate determination of hot-electron lifetimes.