Nonequilibrium states of normal metal films during tunneling injection of electrons

The nonequilibrium states of a metal film in the normal (N) state in an S-I-N-I-S structure (S is a bulk superconductor and I is an insulator) are studied when a voltage V > Δ/e is applied to each tunnel diode in the same direction (Δ is the energy gap of the S electrode and e is the electron charge). Conditions are found in which the energy distribution of electrons near the Fermi surface of the N film is inverted.