Chemical Emissions from Organic Light-Emitting Diode Screens during Use and Thermal Treatment

Abstract

Organic light-emitting diode (OLED) screens are widely used display products today, yet chemical emissions during normal use and end-of-life handling remain poorly characterized. Here, we conducted two complementary experiments: (i) an adsorption-based collection setup coupled with gas chromatography–high-resolution mass spectrometry (GC–HRMS) to characterize emissions during normal screen operation, and (ii) online pyrolysis–GC–HRMS to examine chemicals generated during thermal treatment at end of life. Temperature-programmed pyrolysis (100–600 °C) was used to probe temperature-dependent release, while layer-resolved high-temperature pyrolysis (600 °C) was used to characterize final products and their layer origins: the display functional laminate (DFL) and the module carrier layer (MCL). Thousands of volatile and semi-volatile organic compounds (VOCs/SVOCs) were detected in both scenarios, with VOCs predominating by number. Pyrolysis profiles were strongly temperature- and layer-dependent, with more compounds originating from the MCL than from the DFL. Suspect screening supported by authentic-standard confirmation identified polycyclic aromatic hydrocarbons, benzene derivatives, and phthalate esters in both scenarios, while siloxane-related and selected nitrogen-containing compounds were observed during pyrolysis, potentially reflecting fragments of OLED-related materials. Targeted quantification indicated that phthalate esters, mainly associated with the MCL, dominated the confirmed emissions. These results provide a first molecular-level picture of chemical emissions from OLED screens during use and thermal treatment.