摘要
The fine control of doping levels in graphene materials such as reduced graphene oxide(RGO)is important to properly manipulate their ambipolar transport characteristics for various device applications.However,conventional doping methods involve complex chemical reactions,large-scale doping processes,and poor stability.Herein,a simple and controllable electrochemical doping treatment(EDT),performed via the conductive channels created at the RGO surface by the application of an electric field,is introduced to tailor the electrical properties of RGO films.X-ray photoelectron spectroscopy and Raman spectroscopy measurements are performed to detect the presence of Ni atoms in RGO films after the EDT(EDT-RGO).Then,EDT-RGO field-effect transistors(FETs)are fabricated with different doping areas(0 to 100%fractional area)on the RGO active channel to investigate the effect and selective-area doping capability of the EDT.Owing to p-type doping compensation by the intercalated Ni atoms,the electron mobility of the EDT-RGO FET decreases from 1.40 to 0.12 cm2 V-1s-1 compared with that of the undoped RGO-FET,leading to the conversion from ambipolar to unipolar p-type transfer characteristics.
The fine control of doping levels in graphene materials such as reduced graphene oxide（RGO） is important to properly manipulate their ambipolar transport characteristics for various device applications. However, conventional doping methods involve complex chemical reactions, large-scale doping processes,and poor stability. Herein, a simple and controllable electrochemical doping treatment（EDT）, performed via the conductive channels created at the RGO surface by the application of an electric field, is introduced to tailor the electrical properties of RGO films. X-ray photoelectron spectroscopy and Raman spectroscopy measurements are performed to detect the presence of Ni atoms in RGO films after the EDT（EDT-RGO）.Then, EDT-RGO field-effect transistors（FETs） are fabricated with different doping areas（0 to 100% fractional area） on the RGO active channel to investigate the effect and selective-area doping capability of the EDT. Owing to p-type doping compensation by the intercalated Ni atoms, the electron mobility of the EDT-RGO FET decreases from 1.40 to 0.12 cm2 V-1s-1 compared with that of the undoped RGO-FET,leading to the conversion from ambipolar to unipolar p-type transfer characteristics.
基金
supported financially by the National Research Foundation of Korea(NRF)(No.2016R1A3B1908249).
