Top illuminated organic photodetectors with dielectric/metal/dielectric transparent anode

The top illuminated organic photodetectors (OPDs) with a Dielectric/Metal/Dielectric (DMD) transparent anode are fabricated. The transparent electrode is composed of molybdenum trioxide (MoO 3)/silver (Ag)/MoO 3 layers and zinc oxide (ZnO)/aluminum (Al) is used for bottom cathode. The optimized DMD electrode has an optical transmittance of 85.7% at the wavelength of 546 nm and sheet resistance of $6 O/sq. The fabricated OPDs exhibit a high detectivity and wide range linearity. Over two decades, organic photovoltaics and photode-tectors have been extensively studied due to their easy deposition methods, large-area processing capabilities, and fine tunability of optical absorption coefficients [1,2]. Especially, organic photodiodes (OPD) have been actively studied as potential low-cost, high-performance alternatives to amorphous silicon (a-Si) photodiode for flat panel imagers [3–5]. Among various kinds of the imagers, indirect type imager based on CsI(Tl) scintillator looks very promising for OPD application due to its reduced lateral light scattering, high light output, fast response time, and suitable peak emission spectra [6,7]. Among various organic materials for such application, Poly(3-hexylthioph-ene-2,5-diyl):Phenyl-C 61-butyric acid methyl ester (P3HT: PCBM) bulk heterojunction (BHJ) blend system appears to be very desirable candidate [4,5,7–9]. Ng et al. used 4 lm thick