Aggregation-induced negative differential resistance in graphene oxide quantum dots

Abstract

Negative differential resistance (NDR) devices have attracted considerable interest due to their potential applications in switches, memory devices, and analog-to-digital converters. Modulation of the NDR is an essential issue for the development of NDR-based devices. In this study, we successfully synthesized graphene oxide quantum dots (GOQDs) using graphene oxide, cysteine, and H₂O₂. The current–voltage characteristics of the GOQDs exhibit a clear NDR in the ambient environment at room temperature. A peak-to-valley ratio as high as 4.7 has been achieved under an applied voltage sweep from −6 to 6 V. The behavior of the NDR and its corresponding peak-to-valley ratio can be controlled by adjusting the range of applied voltages, air pressure, and relative humidity. Also, the NDR is sensitive to the the concentration of H₂O₂ added in the synthesis. The charge carrier injection through the trapping states, induced by the GOQD aggregation, could be responsible for the NDR behavior in GOQDs.