Suppression of Leakage Currents in Photo-multiplication Photodetectors with Oxidation-Controlled Metal Interfacial Layer

초록

In this work, we investigate the use of annealed metal oxides in electron blocking layer (EBL) of photo-multiplication organic photodetectors (PM-OPD), to obtain low leakage current, high external quantum efficiency, and thereby, high detectivity. Reliable and high-performance PM-OPD are obtained using multi-interfacial EBLs composed of metals such as Ni, Al, Ag and Au, and their oxides, through a controlled annealing. The interfacial layer between the front electrode and absorption layer is metal-metal oxide layer with wide bandgap, for improved hole mobility and stable electron blocking under the driving voltages of the PM-OPD. Through the optimization of the structural stability of the PM-OPD, a high specific detectivity of 2.59 x 10(13) Jones is obtained under a low reverse voltage. The resulting photodetectors exhibit improved stability under relatively low reverse voltages because of the Schottky barrier induced between the donor and acceptor, electrode components, and passivation effect of the free-electrons driven by the introduced multi-interfacial layers. [GRAPHICS]

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