Electronic Properties of Furan-Quinone Pigments. I. Charge-Transport Studies

Abstract

The electrical properties of a furan‐quinone pigment, 8, 13‐dioxodinaphtho (2, 1−b:2′, 3′−d)‐furan‐6‐(2‐pyridyl)‐carboxamide (DFC), have been studied by means of photoinduced condenser discharge and transient photocurrent techniques. It is shown that the electron range in DFC, ∼10−8 cm2 V−1, is 3 orders of magnitude longer than that of holes, ∼10−11 cm2 V−1. The quantum efficiency of the photogeneration of charge carriers in DFC increases linearly with the square of the electric field, while the dark current increases linearly with the square root of the field. The dark current is determined by the number of free carriers in the bulk and may be described in terms of thermally assisted tunnelling.