Environmental Effects of the Technology Transition from Liquid–Crystal Display (LCD) to Organic Light-Emitting Diode (OLED) Display from an E-Waste Management Perspective

Abstract

Organic light-emitting diode (OLED) displays are applied to various electronic devices such as smartphones and televisions in our society, replacing liquid–crystal display (LCD) due to many advantages: self-emitting property, high contrast, slimness, and flexibility. Although OLED consists mostly of organic substances, because it was developed to reduce the consumptions of rare and precious metals, OLED display has a possibility to contain more metal-based components than LCD; for instance, a pixel circuit for OLED needs two thin-film transistors (TFTs), whereas that for LCD does one. Thus, this study was intended to assess and compare possible environmental impacts due to metals in an OLED display and an LCD on a same screen size basis, to examine environmental effects of the technology transition. Hazardous waste potentials at end-of-life were examined based on metal leachability tests, and resource depletion and toxicity potentials were evaluated based on life cycle impact assessment methods. The leachability test results showed that the OLED display has higher hazardous potential than an LCD due to excessive levels of leachability for many metals under California state regulation. The OLED display had 1000–2300 times higher resource depletion potentials than the LCD due primarily to the high concentrations of gold, selenium, silver, palladium, and tin. The OLED display also had 2–600 times higher toxicity potentials due primarily to the high concentrations of arsenic, cadmium, chromium, and antimony. This study can be used to motivate waste recyclers and managers to actively collect waste OLED displays for circular economy and to direct manufactures to develop more environmental-friendly OLED displays for sustainable society. This study evaluates and compares hazardous, resource depletion, and toxic potentials from metals in a Liquid–Crystal Display (LCD) and an Organic Light-Emitting Diode (OLED) Display to examine the effect of the technology transition on environmental impacts.