High-performance Carbon Nanotube-based Photodetectors Enhanced by SWCNTs/graphene Heterojunction

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