Enabling Localized Surface Plasmon Emission from InGaN/GaN Nano-LEDs Integrated with Ag/SiO₂ Nanoparticles

The development of high brightness, small pixel size, and self-emissive light-emitting diodes (LEDs) is deliberately accelerating to replace conventional organic/inorganic LED displays for the virtual/augmented reality market. In this study, we report the fabrication process of individually well-separated blue-light-emitting InGaN/GaN nanorod LED arrays on a large-scale wafer and detach to disperse them in acetone. The dispersed individual nanorod LEDs are aligned horizontally onto the interdigitated pattern with an alignment yield of ∼90% by applying a sinusoidal electric field at 1 MHz. The inferior electrical connectivity between the aligned nanorod LEDs and the metal electrodes is improved by encapsulating the ends of p-GaN and n-GaN with copper metal, leading to an ∼61-fold enhancement of emission ratio, in comparison. Furthermore, the electroluminescence and photoluminescence efficiencies of horizontally aligned individual nanorod LEDs are improved to ∼1.8- and 2-fold after incorporating Ag/SiO2 nanoparticles (NPs) on the surface of nanorod LEDs. Numerical simulation is performed to evaluate the impact of the localized surface plasmon (LSP) with respect to the SiO2 shell thickness and space between the Ag/SiO2 NPs. The strong LSP coupling effect ensues from the closely integrated Ag/SiO2 NPs on each nanorod LED facilitating an enhanced energy coupling efficiency of 69.4% with a fast decay lifetime of 1.25 ns. Thus, the high brightness and small pixel size of horizontally aligned Ag/SiO2 NPs-embedded monolithic nano-LEDs are suitable for developing next-generation display technology.