Carbon nanotube - graphene composite film high-performance photodetector

Recently, the R & D team led by Professor Wang Fengqiu, Professor Xu Yongbing and Professor Zhang Rong from the School of Electronic Science and Engineering of Nanjing University made important progress in the research field of new low-dimensional material photodetectors. The related paper "Planar carbon nanotube-graphene hybrid films for high-performance Broadband photodetectors "was published online October 8, 2015 in Nature Communications 6 (8589, (2015)).

Graphene is a zero-bandgap 2D material, and its high carrier mobility and broadband photoresponse make it one of the ideal materials for high-performance photodetectors. However, the low absorbance of single-layer graphene and ultra-fast photo-generated carrier recombination process seriously restrict the device's optical responsivity. Based on the abundant control freedom and efficient electron migration at the interface of all-carbon composite materials, the research group proposed to combine "one-dimensional carbon nanotubes and two-dimensional graphene to form" atomic layer thickness "thin film, and it is possible to greatly improve the device's Work performance.

Based on the new all-carbon composite film with high mobility, wide-band light absorption and large-area preparation, the research team first realized a light-detecting transistor based on a single-walled carbon nanotube-graphene composite film. Characterization shows that the new device can operate over the entire visible-near-infrared range (400-1550 nm) with a photoresponsive response of greater than 100 A / W. Even more surprising is the device's response speed of 100 μs due to Van der Waals interactions at the all-carbon interface, which is about three orders of magnitude faster than the graphene-QD system, demonstrating excellent overall performance and usefulness The future In addition, for the first time, this study extends van der Waals heterostructures based on two-dimensional materials to one-dimensional / two-dimensional composite structures. It provides a brand new platform for studying the novel physics phenomenon based on quantum confinement effect in Van der Waals heterojunction. Based on this finding, the research group has applied for a national invention patent and has entered the trial stage.

This research was funded by the State Key Scientific Research Program of Quantum Control, the National Natural Science Foundation of China, the Natural Science Foundation of Jiangsu Province, the Double Team Project of Jiangsu Province, the China Postdoctoral Science Foundation and the Postdoctoral Research Grant Program of Jiangsu Province.