Quantum-Dot Color Conversion Achieved by A Novel Structure of Hollow Cylindrical Blue MicroLED

This study proposes a novel design for achieving color conversion in micro light-emitting diodes (Micro-LEDs) using a hollow cylindrical structure. Instead of printing quantum dots (QDs) on the upper surface of the Micro-LEDs, QDs are printed in a hollow place created by designing hollows of varying sizes and applying a layer of highly reflective metal to the top and outer walls. The design of this structure confines the emission light to the hollows, reduces photon leakage, and increases the path length of the excitation light in the quantum dot area. The color conversion capabilities of 60, 70, 80, and 90 μm hollows were investigated, and a 3×3 array was demonstrated. Using this approach, the thickness of the quantum dots on the upper surface of the LED can be reduced, without the need for a thick black matrix for reducing the problem of light crosstalk. This hollow cylindrical design presents a promising new approach for achieving color conversion in Micro-LEDs, with potential applications in displays and lighting technologies.