ELECTRON PHONON INTERACTION AND HOT-ELECTRONS IN SMALL METAL ISLANDS

We show that at the input of energy into a metal island film hot electrons may be produced there under stationary conditions, with the island lattice remaining cool. In contrast to bulk metals, such a peculiar possibility arises in island films due to the following reasons: (1) the energy losses involving the Cherenkov generation of acoustic modes by hot electrons become minor in a tiny metal island; (2) therefore, one can feed considerable power into a system of small metal islands; (3) a tiny metal island, deposited on an insulating substrate, can transmit considerable fluxes of energy without being damaged (the electron subsystem absorbs energy and carries it along to the substrate). The electron temperature is evaluated and a theory for emission of light by the hot electrons is formulated. In addition, we explain experiments on laser heating of electrons in metal films. © 1990.