Sidewall Suppression and Top Surface Enhancement of Light Extraction Efficiency in Vertically Stacked Full‐Color Micro‐LEDs Based on L‐Shaped Metal Walls

Abstract Micro light‐emitting diodes (Micro‐LEDs) are regarded as the core of next‐generation display technology due to their high brightness and energy efficiency. However, the reduction in the size of Micro‐LEDs has led to increased manufacturing challenges and exacerbated issues such as sidewall emission, which hinder the development of high‐pixel‐density displays. This paper proposes a vertically stacked Micro‐LED design based on an L‐shaped metal wall structure, aiming to suppress sidewall emission and enhance top light extraction efficiency (LEE). Through parameter scanning, the dimensions of the Micro‐LED and the thickness of the epitaxial layer are optimized. Combined with inclined sidewalls and the reflective structure of the L‐shaped metal wall, the optical characteristics of red, green, and blue Micro‐LEDs are analyzed using ray‐tracing simulations. The sidewall emission is significantly reduced (with a maximum reduction of 68.04% compared to vertically stacked Micro‐LEDs without metal walls), and top light emission is enhanced (the LEE within ±90° direction for blue, green, and red light increased by 196.18%, 51.69%, and 3.45%, respectively, compared to stacked Micro‐LEDs without metal walls). The simulation results demonstrate the potential of the L‐shaped metal wall in vertically stacked full‐color Micro‐LED displays, providing a new approach to suppressing optical crosstalk and improving display performance.