The Impact of Luminous Properties of Red, Green, and Blue Mini-LEDs on the Color Gamut

Color gamut is of the paramount importance in the display. Light-current-voltage ( L-I-V ) characteristics of red, green, and blue flip-chip mini-light-emitting diodes (LEDs) ( 100\,\,\mu \text{m}\,\,\times 200\,\,\mu \text{m} ) are investigated at temperatures similar to the operational temperatures. Both the ideality factor and the temperature dependence of external quantum efficiency (EQE) suggest that the nonradiative loss in red mini-LED is higher. We also illustrate the intensive lateral luminous intensity fluctuation for red mini-LED under the over-driving current by capturing the spatial emission mapping. The influence of temperature and driving current on the chromaticity coordinates of mini-LEDs is determined. Furthermore, we propose a drive-current algorithm to maximize the color gamut of the trichromatic mixed light at different temperatures. The results indicate that, for the application of self-emitting mini-LED displays, the maximum color gamut is more sensitive to green emission, whereas enhancing the radiative recombination in red mini-LED could contribute a lot to the improvement on net performance.