Non-Carrier-Injection Quantum Dot Light Emitting Device Based on Internal Field Emission

Quantum dot (QD) light-emitting devices operating in non-carrier-injection electroluminescence (NCIEL) mode have attracted attention due to their extremely simple structure. Since no external carriers are involved in electroluminescence, elucidating the source of carriers required for stable device operation is crucial. It is valuable to understand the mechanism of operation and optimize the device structure. This study focuses on the optoelectronic properties of multilayer QD films in the non-carrier-injection mode. The experimental results show that the luminescence intensity increases rapidly to the maximum value with the increase of AC driving voltage and then decreases gradually. Similarly, the increase in AC driving frequency leads to an initial rise and subsequent decrease in luminescence intensity. In addition, the emission spectra remained consistent in terms of center wavelength and half-peak width at different voltage and frequency settings. Combined with the existence of an insulating organic ligand environment between QDs, a non-carrier-injection luminescence model for multilayer QDs based on the principle of internal field emission is proposed. This study is expected to provide methods for obtaining advanced QD-based light-emitting technology.