A comparative study of graphene and graphite-based field effect transistor on flexible substrate

Abstract

In the present era, there has been a great demand of cost-effective, biodegradable, flexible and wearable electronics which may open the gate to many applications like flexible displays, RFID tags, health monitoring devices, etc. Due to the versatile nature of plastic substrates, they have been extensively used in packaging, printing, etc. However, the fabrication of electronic devices requires specially prepared substrates with high quality surfaces, chemical compositions and solutions to the related fabrication issues along with its non-biodegradable nature. Therefore, in this report, a cost-effective, biodegradable cellulose paper as an alternative dielectric substrate material for the fabrication of flexible field effect transistor (FET) is presented. The graphite and liquid phase exfoliated graphene have been used as the material for the realisation of source, drain and channel on cellulose paper substrate for its comparative analysis. The mobility of fabricated FETs was calculated to be $83\,\hbox {cm}^{2}/\hbox {V}\,\hbox {s}$ (holes) and $33\,\hbox {cm}^{2}/\hbox {V}\,\hbox {s}$ (electrons) for graphite FET and $100\,\hbox {cm}^{2}/\hbox {V}\,\hbox {s}$ (holes) and $52\,\hbox {cm}^{2}/\hbox {V}\,\hbox {s}$ (electrons) for graphene FET, respectively. The output characteristic of the device demonstrates the linear behaviour and a comprehensive increase in conductance as a function of gate voltages. The fabricated FETs may be used for strain sensing, health care monitoring devices, human motion detection, etc.