Optical crosstalk reduction of InGaN micro-LED array based on a reflective wall design for display applications

Optical crosstalk plays a key role in degrading the color accuracy and contrast of GaN-based micro-light emitting diodes (micro-LEDs) in display applications, and a comprehensive solution to this issue remains elusive. In this Letter, we propose a micro-LED array structure featuring individual pixels surrounded by a circular wall deposited with silver (Ag) as a reflective medium, and the effect of crosstalk reduction is well demonstrated. Compared to the conventional micro-LED devices, the luminous intensity distribution mapping indicated that the proposed micro-LED structure achieves a significant light spot reduction under the injection current of about 0.5 mA, and a low-crosstalk display is achieved through a 16 × 16 array. Furthermore, the optical field distribution of the proposed micro-LED structure was studied based on finite-difference time-domain (FDTD) simulation. The results reveal that when the height and gap width of the reflective wall are 5 µm respectively, more than 55 % of the light emission is effectively limited within the ± 45 ∘ divergence angle. This work presents a promising solution for mitigating optical crosstalk in micro-LED displays, thereby enhancing their performance for high-quality display applications.