Inkjet deposition of liquid-exfoliated graphene and MoS₂ nanosheets for printed device applications

Here we demonstrate inkjet printing of nanosheets of both graphene and MoS₂ prepared by liquid exfoliation. We describe a protocol for the preparation of inks of nanosheets with well-defined size distribution and concentration up to 6 mg ml⁻¹. Graphene traces were printed at low temperature (<70 °C) with no subsequent thermal or chemical treatment. Thin traces displayed percolation effects while traces with thickness above 160 nm displayed thickness-independent conductivity of 3000 S m⁻¹. We also demonstrate the printing of semiconducting traces using solvent-exfoliated, size-selected MoS₂ nanosheets. Such traces can be combined with inkjet-printed graphene interdigitated array electrodes to produce all-printed photodetectors.