Calls for sustainable lifecycle approach to organic electronics

Organic electronics can contribute to decarbonisation and, at the same time, help to cut the consumption of rare and valuable raw materials. To do so, it is necessary to further develop manufacturing processes and devise technical solutions for recycling as early as the laboratory phase. Materials scientists from Friedrich-Alexander University (FAU) are now promoting this circular strategy in conjunction with researchers from the UK and USA in the journal Nature Materials.

Organic electronic components, such as solar modules, can be applied in extremely thin layers on flexible carrier materials and therefore have a wider range of applications than crystalline materials. Since their photoactive substances are carbon based, they also contribute to cutting the consumption of rare, expensive and sometimes toxic materials such as iridium, platinum and silver. Organic electronic components are also experiencing growth in the field of OLED technologies, above all for television and computer screens. Professor Doctor Christoph Brabec, Chair of Materials Science at FAU, said that while this is progress, it also causes some problems.

As a materials scientist, Brabec sees the risks of permanently incorporating environmentally friendly technology into a device architecture that is not sustainable on the whole. This can affect electronic devices and also organic sensors in textiles that have a short operating life. “Applied research in particular must now set the course to ensure that electronic components and all their individual parts must leave an ecological footprint that is as small as possible during their entire lifecycle,” Brabec said.

The further development of organic electronics is elementary here, since new materials and more efficient manufacturing processes lead to the reduction of outlay and energy during production. Compared with simple polymers, the manufacturing process for the photoactive layer requires higher amounts of energy as it is deposited in a vacuum at high temperatures. The researchers are proposing cheaper and more environmentally friendly processes, such as deposition from water-based solutions and printing using inkjet processes. However, a major challenge is developing functional materials that can be processed without toxic solvents that are harmful to the environment.

Alongside their efficiency, the operating stability of materials is decisive. Complex encapsulation is required in order to protect the vacuum-deposited carbon layers of organic solar modules, which can make up to two-thirds of their overall weight. More robust combinations of materials could contribute to savings in materials, weight and energy.

To realistically evaluate the environmental footprint of organic electronics, the entire product lifecycle must be considered. In terms of output, organic photovoltaic systems are still behind conventional silicon modules, but 30% less CO₂ is emitted during the manufacturing process. “18% could make more sense environmentally than 20, if it’s possible to manufacture the photoactive material in five steps instead of eight,” Brabec said.

The shorter operating life of organic modules is also relative; although photovoltaic modules based on silicon last longer, they are difficult to recycle. “Biocompatibility and biodegradability will increasingly become important criteria, both for product development as well as for packaging design. We really must start taking recycling into consideration in the laboratory,” Brabec said.

Image credit: iStock.com/WANAN YOSSINGKUM