Optical Crosstalk Among Mini-LEDs Packaged in a Four-in-One Integrated Matrix Device

Optical crosstalk is of paramount importance in mini-light-emitting diode (mini-LED) displays. The influence of the current crowding of mini-LEDs on the optical crosstalk among neighboring pixels of a four-in-one integrated matrix device was determined. The results indicate that when a single mini-LED is powered on, the optical crosstalk decreases as the driving current increases due to the reduction in the ratio of photons emitted from the sidewalls of the mini-LED of interest. The encapsulation over mini-LEDs can enhance optical crosstalk due to the reduction of total reflection at the sidewalls and the effect of the light guide. Furthermore, optical crosstalk at the pixels in the direction perpendicular to the longer edge of the mini-LED of interest is stronger than that at the pixels in the direction perpendicular to the shorter edge. This work also suggests that comprehensive information about optical crosstalk can be obtained by capturing spatially resolved light emission from the upper surfaces of pixels.