Electroluminescence from μLED without external charge injection

Stable electroluminescence from micro-pixelated light-emitting diode (μLED) occurs when electrons and holes are continuously injected from external electrodes. Different from the general recognition, in this work, μLED works in an operation mode, namely, non-electrical contact and non-carrier injection mode, and can be ‘wirelessly’ lit up without external charge injection, which is different from the general recognition. Inherent holes and electrons in μLEDs can provide sufficient carriers for radiative recombination under alternating-current electric field. A possible model related to the diffusion of majority carrier and the drift of minority carrier in μLED was proposed, which is further confirmed by the employment of a ‘carrier pump’. Finally, the intrinsic characteristics of the device-in-capacitor, namely, self-protection against electrical breakdown, were discussed. This work demonstrates a new device configuration and an alternative operating mode for μLED and provides a research manner to obtain advanced μLED-based technology.