Excellent-Performance C₆₀/Graphene/SWCNT Heterojunction with Light-Controlled Enhancement of Photocurrent

Abstract

Carbon allotropes have been widely investigated in photoelectric applications, including single-walled carbon nanotubes (SWCNT), graphene, and C60, due to their high carrier mobility and superior optical properties. Unfortunately, it is proved that the device only by one type of carbon allotropes alone could barely exhibit high performance both in the near-infrared (NIR) range and in the visible-light (VL) range. Here, we demonstrate a broadband photodetector based on all-carbon materials (C60/graphene/SWCNT) which possesses an ultrahigh photoresponsivity (Ri) (>104 A/W @ 450 nm and 545.7 A/W @ 780 nm) in the VL and NIR region, which is beyond that of similar all-carbon-based photodetectors consisting of one type of carbon allotropes. More interestingly, the response time of the NIR waveband can be modulated by the VL waveband as a gate signal. The response time to be modulated will be reduced by an order of magnitude. Meanwhile, the optical modulation mechanism is also thoroughly discussed and analyzed. The combination of high responsivities, tunable operation speeds, and broad bandwidth demonstrates this hybrid film as a potential candidate for energy efficient nanoelectronics.