High-Performance Photodetectors Based on Semiconducting\nGraphene Nanoribbons

Abstract

The inherent zero-band\ngap nature of graphene and its fast photocarrier\nrecombination rate result in poor optical gain and responsivity when\ngraphene is used as the light absorption medium in photodetectors.\nHere, semiconducting graphene nanoribbons with a direct bandgap of\n1.8 eV are synthesized and employed to construct a vertical heterojunction\nphotodetector. At a bias voltage of −5 V, the photodetector\nexhibits a responsivity of 1052 A/W, outperforming previous graphene-based\nheterojunction photodetectors by several orders of magnitude. The\nachieved detectivity of 3.13 × 10¹³ Jones and response\ntime of 310 μs are also among the best values for graphene-based\nheterojunction photodetectors reported until date. Furthermore, even\nunder zero bias, the photodetector demonstrates a high responsivity\nand detectivity of 1.04 A/W and 2.45 × 10¹² Jones,\nrespectively. The work shows a great potential of graphene nanoribbon-based\nphotodetection technology.