The Electroforming Effect in Polycrystalline Fullerene C60 Films

Abstract

Long-term exposure of a polycrystalline fullerene C₆₀ film in a constant electric field of 1–4 MV/cm produces an electroforming effect manifested by increase in conductivity of the film within several orders of magnitude. After this electroforming, the current–voltage (I–U) characteristic shows a high degree of current stability and reproducibility of results. In fields of 10⁵–10⁶ V/cm, the I–U characteristics of electroformed films are determined by the space-charge limited current. The concentration (N_t ≈ 4 × 10²¹ m^–3) of carrier traps and their energy (E_t ≈ 0.176 eV) have been estimated.