Efficiency improvement for micro light-emitting diodes with n-doped quantum barriers and single quantum well

In this article, efficiency performance of blue GaN/InGaN micro light emitting diodes (μ-LEDs) are investigated as functions of chip sizes, quantum barrier doping level and the number of quantum wells (QWs) by simulation. Internal quantum efficiency (IQE) and external quantum efficiency (EQE) drastically decrease with decreasing mesa sizes of μ-LEDs. The simulation indicates that μ-LEDs with n-doped quantum barriers can effectively suppress the Shockley-Read-Hall (SRH) nonradiative recombination and improve the efficiency compared to those with intrinsic quantum barriers in small μ-LEDs. The simulated results also show that decreasing the number of QWs can improve the IQE of μ-LEDs with higher radiative recombination rate in a single QW. An optimized design for 5×5 μm² GaN/InGaN μ-LEDs with n-doped barriers and a single QW shows around 367% efficiency improvement at 1 A/cm² comparing to the conventional intrinsic multiple QWs-based design in simulation.