Simulation Study on the Size Effect and Transient Characteristics of Micro-LEDs

Micro-LED is a promising candidate of the next generation display technology. The size effect caused by sidewall surface traps is a serious issue that restricts its industrialization progress. However, the current research on the size effect of micro-LED is limited to the reduce of quantum efficiency and luminous intensity with decreased pixel size, but there is few research on the mechanism of the transient switching characteristics of Micro-LED affected by sidewall surface traps. In this paper, the size effect of GaN based micro-LEDs is studied by TCAD simulation. The decrease of quantum efficiency is attributed to the depletion effect of the sidewall traps induced by dry etching, the enhancement of SRH non-radiative recombination, and the lateral current component caused by sidewall traps capturing carriers. In addition, the sidewall trap density and trap energy level of micro-LEDs with 10 μm pixel size were varied to study their influence on the transient switching characteristics of micro-LEDs. This work provides a design guideline for the process control of micro-LEDs.