Doping stability and opto-electronic performance of CVD graphene on transparent flexible substrates

The primary barrier to wider commercial adoption of graphene lies in reducing the sheet resistance of the transferred material without compromising its high broad-band optical transparency, ideally through the use of novel transfer techniques and doping strategies. Here, chemical vapour deposited graphene was uniformly transferred to polymer supports by thermal and UV approaches and the time-dependent evolution of the opto-electronic performance was assessed following exposure to three kinds of common graphene dopants. Doping with FeCl3 and SnCl2 showed minor, and notably time unstable, enhancement in the σopt/σdc figure of merit, whilst AuCl3-doping markedly reduced the sheet resistance by 91.5% to 0.29 kΩ/sq for thermally transferred samples and by 34.4% to 0.62 kΩ/sq for UV Kang et al. IET: Graphene Electronics Special Issue 2 transferred samples offering a means to fabricating viable transparent flexible conductors that near the indium tin oxide benchmark.