Field-Effect Passivation of GaN-Based Blue Micro-Light-Emitting Diodes

We demonstrate field-effect passivation (FEP) of GaN-based blue $\mu $ LEDs by incorporating an additional metal-oxide-semiconductor gate structure on the sidewalls. This approach allows for active control of surface band bending at the sidewalls, thereby modulating carrier trapping and de-trapping. We observe that applying a negative gate voltage $(V_{G})$ facilitates electron de-trapping, leading to a reduction in surface recombination and a corresponding decrease in current, as evidenced by an enhanced external quantum efficiency (EQE). Conversely, applying a positive $V_{G}$ results in the opposite effect.