▎ 摘　　要

Graphene quantum dots (GQDs) are becoming one of the hottest advanced functional materials because of the opening of the bandgap due to quantum confinement effect, which shows unique optical and electrical properties. The chlorine doped GQDs (C1-GQDs) have been fabricated by chemical exfoliation of HCl treated carbon fibers (CFs), which were prepared from decreasing cotton through an annealing process at 1000 degrees C for 30 min, Raman study shows that both G and 2D peaks of GQDs may be redshifted (softened) by chlorine doping, leading to an n-type doping. The first vertical (C1)-GQDs based photovoltaic detectors have been demonstrated, both the light absorbing and electron-accepting roles for (C1)-GQDs in photodctection have been found, resulting in an exceptionally big ratio of photocurrent to dark current as high as similar to 10(5) at room temperature using a 405 nm laser irradiation under the reverse bias voltage. The study expands the application of (C1)-GQD5 to the important optoelectronic detection devices. (C) 2014 AIP Publishing LLC.