Printable radiation curable dielectric layers for application in organic electronics

Long Lin – Project Lead  (Leeds)
Patrick Smith (Sheffield)
Stephen Johnson (York)

Organic electronic materials provide a new approach to fabricating light weight, flexible microelectronic devices which can be produced cheaply using large-scale production techniques such as reel-to-reel and inkjet printing. This project will investigate the development of a new low-cost fabrication route to produce multi-material printed electronic devices (OFET and organic photovoltaic cells) by combining the expertise within inkjet printing (Sheffield), materials and assembly of organic electronics (Leeds) and device characterisation (York). The knowledge gained can be extended to other applications such as medical diagnostic sensors.

Dielectric materials are critical in a number of components in electronic circuitry, in particular capacitors, photovoltaics and transistors. Previous attempts at printing dielectrics have had the disadvantage of lack of full crosslinking (thus residual mobile monomers), uneven film formation, leading to the possibility of short circuits, and poor device performance. The proposed work will use inks consisting of radiation curable monomers that are capable of forming defect-free surfaces with uniform thickness. Inorganic nanoparticles may be incorporated where appropriate, which should improve dielectric properties, device reliability and therefore help to enable large-scale manufacture.

The formulation of such dielectric precursor fluids requires highly specialist knowledge, as well as expertise in the fabrication of the organic electronic devices. Co-ordinated by Prof Long Lin, Leeds will provide suitable dielectric formulations to Sheffield who will use their ten years of expertise in inkjet printing to print the devices and control the film morphology. York will characterise the printed materials e.g. via impedance measurements. The efficiency and performance of these new, printed devices will be analysed against existing solutions to determine performance.

The results of each partner will closely feed back in the work being conducted by the others.