Highly Sensitive Broad Organic Photodetector Based on Alumina Interface Modification Layer

Abstract Organic photodetectors (OPDs) have garnered significant attention in the fields of biomedical imaging environmental monitoring and optical communication due to their advantages of material diversity flexibility and biocompatibility.However constrained by the absorption bandgap of organic materials and high dark current exist ing OPDs still face challenges in achieving broadband response and high sensitivity.In this study we choosed the ZnPcC 60 as the active layer and the interfacial chemical reactions between the ITO anode and the ZnPc hole trans port layer were effectively suppressed by introducing an aluminum oxide interface modification layer.Thus the dark current density of the device was reduced to 410 -7 A/cm and the light-to-dark current density ratio of the device was increased to 3 500.Furthermore Raman spectroscopy confirms that there is an intermolecular charge transfer effect between ZnPc and C 60 which effectively broaden the response range of the device with stable spectral response char acteristics of 375-1 550 nm.After further optimization the device yielded an external quantum efficiency (EQE)