Electroluminescent devices via soft lithography

Abstract

This thesis provides a compendium for the use of microcontact printing in fabricating electrical devices. Work has been undertaken to examine the use of soft lithographic techniques for employment in electronic manufacture. This thesis focusses on the use of high electric field generators as a means to producing electroluminescent devices. These devices provide a quantifiable output in the form of light. Analysis of the electrical performance of electrode structures can be determined by their success at producing light. A prospective reduction in driving voltage would deem these devices more efficient, longer lasting and an improvement on current specification. The work focussed on the viability of using relatively crude print techniques to create high resolution structures. This was carried out successfully and demonstrated that lighting structures of 75 μm and 25 μm have been produced. Microcontact printing has been established as a method for patterning gold surfaces with a functionalising self-assembled monolayer using alkanethiol molecules. This layer is then utilised as an etch resist layer to expose gold tracks for use as electric field generator electrode arrays. Through careful analysis of each step of the printing process, techniques were developed and reported to create a robust and repeatable print mechanism for reliability and accuracy. These techniques were employed to optimise the print process culminating in the development of each stage and final electrode structures mounted on a rigid backplate for use as electroluminescent devices for characterisation. These devices were then modelled for their electrical characteristics and investigated for being used in low voltage application. In this case for the development of electroluminescent applications, a driving voltage of 65 V was achieved and represents a significant advance to the field of printed electronics and Electroluminescence.