Graphene quantum dots (GQDs) were synthesized and incorporated with polyethylene dioxythiophene:poly(4-styrenesulfonate (PEDOT:PSS), Ag nanowires (AgNWs) to form a composite that can be used for enhancement of relative humidity (RH%) sensing. The composite films contained bulk heterojunctions of AgNW/GQD and AgNW/PEDOT:PSS. The sensors made from the composites responded well to relative humidity in a range from 10% to 50% at room temperature. | VNU Journal of Science: Mathematics – Physics, Vol. 33, No. 3 (2017) 51-59 Characterization of Humidity Sensing of Polymeric GrapheneQuantum-Dots Composites Incorporated with Silver Nanowires Lam Minh Long1, Nguyen Nang Dinh1,* Hoang Thi Thu2, Huynh Tri Phong2, Tran Quang Trung2 1 University of Engineering and Technology, Vietnam National University, Hanoi 144 Xuan Thuy, Hanoi, Vietnam 2 University of Natural Science, Vietnam National University, Ho Chi Minh City 227 Nguyen Van Cu Road, District 5, Ho Chi Minh City Received 07 August 2017 Accepted 19 September 2017 Abstract: Graphene quantum dots (GQDs) were synthesized and incorporated with polyethylenedioxythiophene:poly(4-styrenesulfonate) (PEDOT:PSS), Ag nanowires (AgNWs) to form a composite that can be used for enhancement of relative humidity (RH%) sensing. The composite films contained bulk heterojunctions of AgNW/GQD and AgNW/PEDOT:PSS. The sensors made from the composites responded well to relative humidity in a range from 10% to 50% at room temperature. With an AgNWs content ranging from wt.% to wt.% and wt.%, the sensitivity of the relative humidity sensing devices based on AgNWs-doped GQDs+PEDOT:PSS composites was increased from to % and %, respectively. The response time of the composite sensors was much improved due to AgNWs doping in the composites. For the wt.% AgNWs-doped GQDs+PEDOT:PSS films, the best value of the recovery time was found to be of 30 s. Keyword: Graphene humidity sensing. quantum dots (GQDs), Ag-nanowires (AgNWs), nanocomposite, 1. Introduction Since graphene was discovered, isolated and characterized in 2004 by Geim and Novoselov [1], numerous scientific works have been increasingly done on the application of graphene. This is because graphene possesses many excellent electrical properties, since it is an allotrope of carbon with a structure of a single two-dimensional (2D) layer of sp2 hybridized carbon atoms. Graphene quantum dots (GQDs),
