Direct Observation of High Photoresponsivity in Pure Graphene Photodetectors.
Ultrafast and broad spectral bandwidth photodetectors are desirable attributable to their unique bandstructure﻿s. Photodetectors based on graphene have great potential due to graphene's outstanding optical and electrical properties. However, the highest reported values of the photoresponsivity of pure graphene are less than 10 mA/W at room temperature, which significantly limits its potential applications. Here, we report a photoresponsivity of 32 A/W in pure monolayer graphene photodetectors, an improvement of over one order of magnitude for functional graphene nanostructures (<3 A/W). The high photocurrent generation in our devices can be attributed to the high sensitivity of graphene's resistivity to a local change of the electric field induced by photo-excited carriers generated in the light-doping substrate. This dramatically increases the feasibility of using graphene for the next generation of photodetectors.
Hunan Key Laboratory for Super-microstructure and Ultrafast Process, School of Physics and Electronics, Central South University, 932 South Lushan Road, Changsha, Hunan, 410083, People's Republic of China.|Department of Materials Science and Engineering, University of California, Berkeley, California, 94720, USA.
Yanping
Y
Liu
Hunan Key Laboratory for Super-microstructure and Ultrafast Process, School of Physics and Electronics, Central South University, 932 South Lushan Road, Changsha, Hunan, 410083, People's Republic of China.
Qinglin
Q
Xia
Hunan Key Laboratory for Super-microstructure and Ultrafast Process, School of Physics and Electronics, Central South University, 932 South Lushan Road, Changsha, Hunan, 410083, People's Republic of China.
Jun
J
He
School of Chemical and Biomolecular Engineering, The University of Sydney, Sydney, NSW, 2006, Australia. zongwen.liu@sydney.edu.au.
Zongwen
Z
Liu
Graphene; Lightly p-doped substrate; Photodetector; Photoresponsivity