Effect of P-Electrode Area Ratio on Micro-LED Optoelectronic Performance

The P-electrode is essential for achieving uniform current distribution within the chip, which directly affects the device optoelectronic performance. In this study, micro-LEDs of varying sizes (22, 34, and <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$46~\mu $ </tex-math></inline-formula>m) and P-electrode area ratios (20%, 30%, and 40%) were fabricated and analyzed. The findings reveal that the optoelectronic performance of micro-LEDs smaller than <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$50~\mu $ </tex-math></inline-formula>m is significantly affected by different P-electrode area ratios under low current density conditions. This effect primarily results from the combined influence of current distribution and the light-blocking properties of the P-electrode metal. To characterize the performance of these micro-LEDs, hyperspectral imaging and COMSOL simulations were employed. The insights gained from these results provide valuable guidance for the design and fabrication of micro-LEDs optimized for low current density operation.