Environmental assessment of OLED lighting foils

Abstract

The development of OLED lighting foils is currently at a stage that choices can still be made between different materials and process options. Holst Centre acknowledges the need to include the environmental impact of these choices as a factor in the consideration during development. To assess the environmental impacts of these choices, the environmental impacts of five different OLED designs were assessed and compared in detail. The goals of this study were: to give insight in the environmental impacts of the entire life cycle of the five different OLED lighting foils, to identify the main sources of environmental impact, to give a comparison between the five different OLED designs and to identify gaps in scientific knowledge on OLED environmental impacts. The main differences between the five designs were the materials used for anode manufacturing and the substrate material used: the ‘Printed Ag’ and ‘Printed Cu’ OLEDs have a printed silver or copper anode, the ‘Fast2light’ and ‘Embedded’ OLEDs have an electroplated copper/gold anode, while the ‘Top emission’ OLED is based on a different principle where the light escapes from the opposite site in relation to the other flowcharts. All but the Top Emission OLED are produced on a transparent, plastic substrate. The Top Emission OLED is produced on an aluminium or copper foil substrate. Two different end of life scenarios were considered: precious metal recycling and municipal solid waste incineration. One of the identified gaps in scientific knowledge was the potential environmental risk of nano silver use in OLED manufacturing. A literature study was performed on this subject to assess this potential environmental risk.

The main conclusions include that the Printed Cu OLED has the lowest environmental impact of all compared OLED designs. For the designs using silver, the end of life impacts resulting from silver use have significant contribution.