Low dark-current and high-photodetectivity transparent organic ultraviolet photodetector by using polymer-modified ZnO as the electron transfer layer.

Abstract

In this Letter, a transparent organic photodetector (OPD) with a property of ultraviolet sensitivity is demonstrated by using an inverted architecture. A conjugated polymer of ploy [(9,9-bis(3'-(N,N-dimethylamino)propyl)-2,7-fluorene)-alt-2,7-(9,9-dioctyl)fluorene)] is introduced to modify the energy level and morphology between ZnO and organic optoelectronic material. As a result, at a wavelength of 350nm and a bias of -1 V, the photodetectivity of 1012 Jones from both sides of the transparent device is obtained with a working area of 1 cm2. Moreover, an optical simulation is applied to analyze the optical electric field distribution inside the OPD.