Field effect transport properties of electrochemically prepared graphene quantum dots

Herein we report the field effect properties of lithographically fabricated FET with graphene quantum dots (GQDs) as channel. GQDs are synthesized via an electrochemical avenue using multiwall carbon nanotubes. As-prepared dots of 4.5±0.55 nm average diameter are found to be p-type in nature under ambient conditions. Field effect measurements yield hole mobility of 0.01 cm² V^-1s^-1 and I_on/I_off ratio of 45. After annealing of devices in Argon atmosphere at 300°C for 20 min, the channel is found to show ambipolar transport with significant increase in resistance.