BROADBAND POLYMER PHOTODETECTORS USING ZINC OXIDE NANOWIRE AS AN ELECTRON-TRANSPORTING LAYER

摘要

A polymer photodetector has an inverted device structure that includes an indium-tin-oxide (ITO) cathode that is separated from an anode by an active layer. The active layer is formed as a composite of conjugated polymers, such as PDDTT and PCBM. IN addition, a cathode buffer layer formed as an matrix of ZnO nanowires is disposed upon the ITO cathode, while a MoO₃ anode buffer layer is disposed between a high work-function metal anode and the active layer. During operation of the photodetector, the ZnO nanowires allows the effective extraction of electrons and the effective blocking of holes from the active layer to the cathode. Thus, allowing the polymer photodetector to achieve a spectral response and detectivity that is similar to that of inorganic photodetectors.