Sustainable Manufacturing of Transparent Conducting Oxide (TCO) Inks and Thin Films
Reduction and elimination of indium and other rare materials usage in the manufacture of transparent conductive oxide (TCO) products are urgently needed to sustain continued growth of the electronics/displays and photovoltaic (PV) industries.
As the mainstream transparent conductive oxide (TCO), indium tin oxide (ITO) offers excellent electrical conductivity and optical transparency. This makes it absolutely essential in the manufacture of displays and solar cells. However, the high demand, comparative scarcity and volatile price of indium have necessitated the search for the reduction and substitution strategies for ITO.
At Loughborough University, we have been taking two approaches to address the sustainable manufacture of TCO products:
- by zero loss manufacturing and considerably reduced usage of ITO;
- by development of earth-abundant TCO alternatives (containing zinc, aluminium, titanium elements) to replace ITO.
The project is focused on developing industry-relevant outcomes in low-e windows, computers, tablets, phones and PV applications.
In collaboration with UCL and 16 industrial partners, we have drawn on a range of low-loss, inexpensive and scalable processing routes (e.g. aerosol-assisted chemical vapour deposition, chemical bath deposition, nanoparticle ink drop-casting/printing, rapid CO2 laser sintering and microwave sintering) to prepare a range of indium-lean or indium-free TCO products with equivalent or better figures of merit to existing ITO products.
Selected Research Publications:
- We have developed a material-efficient deposition and fast laser sintering route for multi-component ITO-GZO nanoparticle thin films and patterns, which enables >60% less indium usage, optoelectronic property modulation, 10 times faster production and custom design of pattern. Full publication.
- We have developed a high-throughput and energy-efficient microwave-based sintering approach for TCO nanoparticle coatings. Full publication.
- We have developed a low-cost and facile aerosol-assisted fabrication route for TCO coatings from nanoparticle dispersions. Full publication.
Professor Paul Conway - Dean of School, Professor of Manufacturing Processes and Director, EPSRC Centre for Doctoral Training in Embedded Intelligence
“Transparent conducting oxides are one of those groups of materials that we are all utilising in our daily lives but not aware of the challenges faced by manufacturers in continuing to deliver products that rely on them for their function. These include our mobile phone, laptop, computer and television screens and in solar cells. Industry has already made steps to significantly increase the recycling efforts, however demand for the products and hence materials still places a strain on the supply chains to deliver these materials. We have taken two approaches, significantly increasing the resource efficiency of TCO material processing options and exploring alternative materials systems to reduce costs while maintaining performance.”