Light-emitting MOS junction for ultrahigh-resolution quantum dot displays

A high-resolution quantum-dot (QD) light-emitting device array is considered to be the key component in a high resolution near-eye micro-display. Although much research has been committed to the achievement of a high-resolution QD pattern, realizing a sub-10 micrometer or even a sub-micrometer device array is challenging because of the requirement for precise vertical multilayer alignment and the existence of electric-crosstalk effects. In this work, we propose a QD-based light-emitting metal/oxide/semiconductor junction (LE-MOSJ) with a super-simple structure of ITO/Al2O3/QDs/Ag with no injection or transfer layer. We measured the voltage-frequency-electroluminescence, spectrum-voltage, and spectrum-frequency characteristics, used voltage-dependent time-resolved electroluminescence to analyze the carrier transport behavior and the working mechanism, and attribute the electron source for the electroluminescence to free and surface defect-captured electrons. Finally, we successfully demonstrate an ultrahigh-resolution LE-MOSJ array with ∼4200 pixels per inch (PPI). We believe the proposed LE-MOSJ can provide an optional approach for realizing ultrahigh-resolution QD-based display technology.