Enhancing the Performance of InGaN-Based Micro-LED Arrays via Fluorine Ion Implantation Passivation Ring Design

Micro light-emitting diodes (micro-LEDs) based on gallium nitride (GaN) semiconductors are considered revolutionary technology for microdisplays and virtual displays. However, micro-LEDs still suffer from severe efficiency droop caused by sidewall damage during pixelation when the pixel sizes are reduced to about 10 μm or less, hindering their prospects in the fields of commercial applications. Here, we proposed a novel mesa structure design with ion implantation passivated side edges for fabricating enhanced-performance micro-LED arrays. High-resistivity insulation areas in the P-GaN layer induced by tailored F– ion implantation surround active light-emitting areas to keep the injection current path far away from sidewall defects. It concludes that, by the additional tailored F– ion implantation process, the photoelectric properties are significantly improved, including leakage current, light output power, luminous efficiency, and color purity for the as-fabricated ultrasmall InGaN-based blue micro-LEDs with pixel sizes of 10, 8, and 6 μm. Additionally, the proposed novel pixelation process conducted by ion implantation plus selective etching can also conduce to enhancing light extraction efficiency and reducing optical crosstalk, in contrast to the as-reported planar pixelation process. This work provides an effective method to improve the performance of ultrasmall micro-LED arrays through fabricating fluorine ion implantation passivated mesas.