Heavy metal-free white light-emitting diodes based on multinary copper chalcogenide nanocrystals

Quantum dot (QD) white light-emitting diodes (WLEDs) have been aimed at improving high-color gamut displays and solid-state lighting yet faced scrutiny due to the toxicity of Cd. We have successfully fabricated WLEDs with a high color rendering index of 93 via heavy metal-free multinary copper chalcogenide nanocrystals. The devices demonstrate a maximum luminance of 1062 cd/m² and a peak external quantum efficiency (EQE) value of 1.15%. Notably, these devices exhibit minimal efficiency roll-off, maintaining an EQE value of 1.09% even at elevated luminance levels (500 cd/m²). This investigation presents a compelling methodology for fabricating WLEDs and holds significant promise for potential applications.