Photoinjection into polyethylene terephthalate

Abstract

We have measured the photocurrents injected into polyethylene terephthalate from evaporated aluminum electrodes in the wavelength range 475–300 nm following a careful depolarization of the specimens. The yield curves give linear plots of (yield)1/2 against photon energy. The threshold energy is [Formula: see text]. Using fields up to 4 × 105 V cm−1, the threshold falls at a rate consistent with Schottky injection of holes, while the yield itself increases as expected for geminate recombination. Our yield results agree with those obtained using electron beam excitation, but differ from the case of hard X-ray irradiation.