All-printed dielectric capacitors from high permittivity, liquid-exfoliated BiOCl nanosheets

Abstract

Printed networks of insulating 2D materials are promising for dielectric applications in printed electronic devices. However, this work has not really progressed beyond networks of BN nanosheets displaying dielectric constants of <6. Here we use liquid phase exfoliation to demonstrate the production of nanosheets from the high permittivity, layered material BiOCl. We first demonstrate liquid exfoliation of BiOCl nanosheets followed by the characterisation of the resultant suspensions. We then use aerosol jet printing to print capacitors from patterned heterostacks, consisting of BiOCl nanosheets networks sandwiched between networks of liquid exfoliated graphene nanosheets. We characterise these capacitors as a function of network thickness, finding a high network dielectric constant of >40 but a relatively low dielectric strength of 0.67 MV/cm. We also observe an unexpected series capacitance which we attribute to an internal capacitance associated with inter-nanosheet junctions within the graphene electrodes.