Hysteretic response of chemical vapor deposition graphene field effect transistors on SiC substrates

Abstract

Graphene field effect transistors (GFETs) fabricated by chemical vapor deposition graphene deposited onto SiC substrates exhibit sensitivity to broadband visible light. The hysteretic nature of this GFET type was studied utilizing a new current-voltage measurement technique in conjunction with current-time measurements. This measurement method accounts for hysteretic changes in graphene response and enables transfer measurements that can be attributed to fixed gate voltages. Graphene hysteresis is shown to be consistent with electrochemical p-type doping, and current-time measurements clearly resolve a hole to electron to hole carrier transition in graphene with a single large change in gate voltage. V

Position-dependent and millimetre-range photodetection in phototransistors with micrometre-scale graphene on SiC

“…The small offset of the zero crossing point of the photocurrent away from V g = 0 V ( Fig. 1d) may be related to gate hysteresis and trapped charges in the SiC 27 .…”

Modulation of graphene field effect by heavy charged particle irradiation

“…The gate voltage at which all the field effect curves intercept is expected to be V g ¼ 0 V. Due to a possible combination of the effect of built-up charge in the substrate and doping of graphene by the ambient environment and during fabrication, the intercept gate voltage is shifted to positive V g , whereby an additional application of electric field is required to induce an effective zero doping in graphene. [45][46][47][48] Time-dependent measurements of graphene current resulted in a greater rate of change of I sd when GFET was exposed to the higher activity 241 Am source compared to the lower activity 210 Po source, as shown in Figs. 3(a) and 3(b).…”

Effects of electron beam induced Redox processes on the electronic transport in graphene field effect transistors

“…Additional exposure to air for 20 minutes completely eliminated the hysteresis. In general, transport hysteresis in graphene appears due to charge carrier traps and polar molecules on graphene or the interface between graphene and the substrate [9,11,15]. Although the origins of hysteresis have been extensively studied in various conditions, the hysteresis in GFET devices as a result of electron irradiation…”

“…In particular, ambient molecules surrounding graphene induce electrochemical doping [10,11], which deteriorates the transport properties [9,10]. Furthermore, hysteresis appears due to these ambient molecules as the gate voltage is swept in opposite directions [12][13][14][15][16].…”