Humidity sensor and ultraviolet photodetector based on carrier trapping effect and negative photoconductivity in graphene quantum dots

• 来源期刊: 中国科学:物理学 力学 天文学（英文版）
• 年，卷（期）: 2018,（1）
• 页码范围: 51-56
• 页数: 6页
• 语种: 英文
• DOI: 10.1007/s11433-017-9089-6

摘要

We report on the experimental realization of a graphene quantum dots (GQD)-based humidity 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％.