Effects of the P-Electrode Area Ratio on the Performance of Micro Light-Emitting Diodes for Display and Communication

In this letter, green micro-LEDs with a chip size of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$27 \; \mu $ </tex-math></inline-formula>m and different P-electrode area ratios (20%, 30%, 40%, and 50%) were fabricated and characterized to determine the optimal P-electrode area ratio for display and communication. The results showed that increasing the P-electrode area ratio improved the uniformity in the current distribution of the micro-LED. However, it can also cause significant metal light-blocking. The optimal P-electrode area ratio of the micro-LED for displays was 30%, yielding optimal external quantum efficiency (EQE) and light output power (LOP). The optimal P-electrode area ratio of the micro-LED for communication was 50%, resulting in a marked improvement in the normalized frequency response and -3 dB bandwidth. It is crucial to select the appropriate P-electrode area ratio for the micro-LED depending on the applications.