Photoelectric properties of tetracene‐pentacene heterojunction

Abstract We investigated vacuum‐evaporated sandwich systems formed by two organic layers of pentacene and tetracene. We measured spectral dependences of photovoltaic short‐circuit currents and photocurrents as well as current‐voltage dependences. In the case of systems equipped with Au and CuI electrodes the structure of spectral characteristics is determined by exciton release of trapped charge carriers either in the bulk of tetracene or near tetracene‐pentacene interface and by photogeneration in pentacene layer. For systems with two Au electrodes we can also observe an influence of exciton injection of holes into tetracene on spectral characteristics. The measurements of dark current‐voltage characteristics allow to observe the presence of a potential barrier between tetracene and pentacene.