Improvement of the Internal Quantum Efficiency of III-Nitride Blue Micro-Light-Emitting Diodes by the Hole Accelerator at the Low Current Density

Abstract

The hole accelerator is proven to benefit the hole injection for traditional light-emitting diodes (LEDs) because the induced electric field provides the holes with more kinetic energy to pass through the electron-blocking layer, enhancing the hole injection efficiency. Herein, the effect of the hole accelerator (HA) layer on the micro-LEDs by modeling the characteristics of the devices with a current density of lower than 10 A cm⁻² is investigated. The simulation results show that the appended HA layer brings a knot of the electric field in the HA layer, leading to higher internal quantum efficiency (IQE) than the device without HA under the low current density. The thickness and composition of HA, the quantum number, and the material of quantum barrier are also simulated and analyzed. The simulated radiative, Shockley–Read–Hall, and Auger recombination rates show that the IQE of the micro-LED with the HA layer is higher than that without the HA layer under the current density of lower than 10 A cm⁻².