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

This paper proposes a novel approach to achieve color conversion in micro light-emitting diodes (Micro-LEDs) using a hollow cylindrical design, which allows the printing of quantum dots (QDs) in a hollow place. By varying the sizes of the hollows and applying a highly reflective metal layer to the top and outer walls, the emission light can be confined to the hollows, reducing the leakage of photons and increasing the path length of the excitation light in the quantum dot area. We investigated the color conversion capabilities of 60, 70, 80, and 90 um hollows, and demonstrated a 3x3 array. This approach reduces the thickness of the quantum dots on the LED surface and eliminates the need for a thick black matrix, thereby reducing the problem of light crosstalk. This hollow cylindrical design has potential applications in displays and lighting technologies.