High-performance self-driven near-infrared photodetector based on single-walled carbon nanotube/graphene/Al2O3/InP

Abstract

Carbon nanotube (CNT) is one of the typical materials for near-infrared photodetectors. Combining its ultra-high mobility, excellent infrared absorption, and suitable energy band structure with graphene and semiconductors, it greatly improves the photodetector performance. This paper reports a self-driven near-infrared photodetector of single-walled carbon nanotubes (SWCNTs)/single-layer graphene/Al 2 O 3 /P-type InP structure, the photocurrent of the device is greatly improved with the help of SWCNTs, and the Al 2 O 3 layer improves the Schottky barrier between InP and graphene, which can suppress the carrier recombination on the semiconductor surface. This device structure exhibits a highly sensitive photoresponse at 808 nm, and at zero under the bias condition, the responsivity reaches 154.3 mA·W -1 , and the detection rate reaches 1.27 × 10 12 Jones. It has a fast response time of microsecond level, and can meet the detection requirements in the mid-frequency range. This result is expected to provide ideas for further optimization on single-walled carbon nanotubes in near-infrared photodetectors. • A monolayer graphene/InP Schottky junction near-infrared photodetector with SWCNTs is fabricated. • The combination of SWCNTs and graphene greatly improves the responsivity, detectivity, and quantum efficiency of the device. • The interface passivation technology of Al 2 O 3 effectively reduces dark current. • The ballistic transport mechanism of SWCNTs enables the device with microsecond response time.