Roll to Roll Manufacturing of Transparent Conductive Electrodes Using Cu Nanowires – MSc Group Project 2015-2016 at Cranfield University
Today ITO (indium tin oxide) is the most used material for organic solar cells, LED (light emitting diodes) and touchscreens, despite several drawbacks. Indium is rare and toxic, ITO is brittle and these characteristics are not suitable to today’s devices. To overcome these problems, different techniques in relation to the mass production of cheap transparent electrodes using copper or silver nanowires have been developed.
Aim and Objectives
The aim of this project was to produce a spreadable ink with a customised scaled laboratory machines to simulate the industrial one. This research was undertaken in order to achieve a high conductivity with low cost copper nanowires. The project also included the development of a print head that can be adapted into a roll to roll system to enlarge from the laboratory scale to the industrial production.
In order to increase the performances, the group decided to focus on the amount of organic dispersant to be used for the dispersion of the nanowires, decreasing also the amount of solvents used. Other problems, such as formation of bubbles and the weak binding to the substrate of the film were overcome during the project by refining the techniques used for the post treatment. The ink configuration was spread with the Meyer rod and the results were used to assess if the process could be brought to a larger scale with the printing head that the group were developing.
Having analysed the results with different techniques (conductivity test, SEM, OM, transparency test, bending test), the group demonstrated the possibility of this process to be brought to a larger scale, even if some characteristics of the film are still not comparable to the ITO. The group also developed a cost effective way to adjust a diamond turning machining to work as a slot die coater, with a printing head that could easily be adapted into one of the existing roll to roll platforms at Cranfield University.
Group Project Team Members
Mr Raffaele D’Addario, Mrs Adriana Karcz, Mr Ansab Khalid, Mr Luis Rubio Garcia and Mr Wei Wang.
D’Addario, R., Karcz, A., Khalid, A., Rubio Garcia, L., Wang, W., Huang, Z., Endrino Armenteros, J., Comley, P. and Lonne, Q. (2016). Roll to Roll Manufacturing of Transparent Conductive Electrodes using Cu Nanowires, Manufacturing, Materials and Design Group Project Presentation Day, 29 April 2016, Cranfield University, UK.