A simple and effective method for the preparation of amphiphilic graphene(AG)is presented under an organic solvent-free synthetic condition.The synthetic route first involves a cyclization reaction between carboxylic groups on graphene oxide and the amino groups on 5,6-diaminopyrazine-2,3-dicarbonitrile,and subsequent reduction by hydrazine.Results of UV-vis spectroscopy,Fourier transformed infrared spectroscopy(FT-IR),X-ray photoelectron spectroscopy(XPS),thermogravimetric analysis(TGA)and Raman spectroscopy have confirmed that the covalent functionalization of graphene can be achieved through the formation of imidazo[4,5-b]pyrazine on the graphene sheets.As a result,AG can be successfully dispersed in water and common organic solvents.This work successfully provides a facile and efficient way to fabricate AG and may extend the potential applications of graphene-based materials in nanoelectronic devices,polymer fillers and biological field.
We fabricated heterojunction organic field-effect transistors(OFETs) using copper phthalocyanine(Cu Pc) and hexadecafluorophtholocyaninatocopper(F16CuPc) as hole transport layer and electron transport layer,respectively.Compared with F16CuPc based OFETs,the electron field-effect mobility in the heterojunction OFETs increased from 3.1103 to 8.7103cm2/(V s),but the p-type behavior was not observed.To enhanced the hole injection,we modified the source–drain electrodes using the MoO3 buffer layer,and the hole injection can be effectively improved.Eventually,the ambipolar transport characteristics of the CuPc/F16 CuPc based OFETs with a Mo O3 buffer layer were achieved,and the field-effect mobilities of electron and hole were 2.5103 and 3.1103cm2/(V s),respectively.
