We report on the experimental realization of a graphene quantum dots （GQD）-based htunidity sensor and ultraviolet （UV） photodetector. We demonstrate that the conductance of the GQD increases linearly with increasi...We report on the experimental realization of a graphene quantum dots （GQD）-based htunidity sensor and ultraviolet （UV） photodetector. We demonstrate that the conductance of the GQD increases linearly with increasing relative humidity （RH） of the surrounding environment due to the carrier trapping effect, which forms the basis of a humidity sensor. When the sensor is operated in the dark state, the sensitivity can reach as high as 0.48 nS RH-^1. The GQD are also found to exhibit light intensity dependent negative photoconductivity under the UV irradiation, which can be exploited for UV detection. As a result of these carrier trapping and de-trapping processes, the performance of the photodetector can be significantly improved with the increasing RH, and the photoresponsivity can reach a high value of-418.1 μA W^-1 in the high humid state of RH=90%.展开更多
基金supported by the State Key Program for Basic Research of China(Grant No.2013CB632703)the National Natural Science Foundation of China(Grant Nos.11674168,11474215,and 11621091)the Scientific Research Foundation of Graduate School of Nanjing University(Grant No.2015CL01)
文摘We report on the experimental realization of a graphene quantum dots （GQD）-based htunidity sensor and ultraviolet （UV） photodetector. We demonstrate that the conductance of the GQD increases linearly with increasing relative humidity （RH） of the surrounding environment due to the carrier trapping effect, which forms the basis of a humidity sensor. When the sensor is operated in the dark state, the sensitivity can reach as high as 0.48 nS RH-^1. The GQD are also found to exhibit light intensity dependent negative photoconductivity under the UV irradiation, which can be exploited for UV detection. As a result of these carrier trapping and de-trapping processes, the performance of the photodetector can be significantly improved with the increasing RH, and the photoresponsivity can reach a high value of-418.1 μA W^-1 in the high humid state of RH=90%.
