High-Performance Carbon Nanotube-Based Photodetectors Enhanced by SWCNTs/Graphene Heterojunction

Abstract

Photodetectors have attracted considerable attention for applications in optical telecommunications, imaging, and environmental monitoring. In this article, a broadband (visible to near infrared) photodetector based buried-gate field-effec transistor was fabricated with a high photoresponsivity of 1091 A/W (at 590 nm) and 314 A/W (at 940 nm) using transparent single-walled carbon nanotubes (SWCNTs) films at room temperature. On this basis, the photoresponsivity of photodetectors can be further improved to 2842 A/W (at 590 nm) and 1043 A/W (at 940 nm) by constructing SWCNTs/graphene heterojunction, which is nearly 3 times higher than that of SWCNTs photodetectors. The comparison of the optoelectrical performance of these two devices further confirms that forming the SWCNTs/graphene all-carbon heterojunction facilitates the separation and transport of photogenerated carriers, thereby providing a feasible pathway for high-performance, miniaturized, large-scale, and broadband photodetectors. This work brings insight into the development of all-carbon hybrid-based high-performance photodetectors in the future.