Cold-Trap-Mediated Broad Dynamic Photodetection in Graphene-Organic Hybrid Photonic Barristors.

Abstract

One of the most popular approaches to improve the performance of organic photonic devices has been to control the electrically heterogeneous charge-transferring interfaces via chemical modifications. Despite intense research efforts, however, the rapid pace of material evolution through the chemical versatility of the organic compound allows only limited room for the fine-tuning of the interfaces exclusive to specific materials. This limitation leads to an ill-controlled charge recombination behavior that relies solely on the inherent characteristics of each material; thus, the common device architecture cannot harness its full potential. In this work, we demonstrate the use of a graphene-organic hybrid barristor-type phototriode architecture as an alternative platform to realize a linearly and highly photosensitive photodetector operating in a broad dynamic range with rapid temporal responses. With the capability of interfacial energetic modulation, our model system exhibits the dominance of swiftly saturable and slowly responding "cold" traps (TC < 3kT) in charge recombination behaviors, leading to a broad linear dynamic range of 110 dB as well as unconventional illumination-driven increments of both D* and R up to 1013 Jones and 360 mA/W, respectively, that surpass the best-reported organic photodiodes. Our findings demonstrate that the organic-graphene hybrid photonic barristor architecture can open new avenues to design high-performance photodetectors for various photonic applications in the future.