Asymmetric Quantum-Dot Pixelation for Color-Converted White Balance

Pixelated quantum-dot color conversion film (QDCCF) is attractive for next-generation, high-pixel-density, full-color displays. However, how to achieve white balance of these QD converted displays puts forward a new challenge, because the final light-emitting area is redefined by the apertures of the QD formed subpixels. Based on this, this paper presents an effective white-balance realization approach by precisely defining an asymmetric aperture ratio among three primary-color subpixels of the QDCCF. Based on the measured photoluminescence characteristic of quantum-dot photoresist (QDPR), the theoretical aperture ratio can be derived by the spectral radiation energy and external quantum efficiency (EQE) of QDCCFs for the target D65 white-balance state. A bilayered device architecture, combining a blue mini-LED backlight and a pixelated QDCCF, was simulated and experimentally assembled to verify the theoretical design. The simulated chromatic coordinates obtained from the QDCCF precisely agree with the target white-balance point. Experimental patterning and pixelation of the designed QDCCF were achieved by a precise photolithography process. Measured results show that a white-light output was achieved with the chromatic coordinates of (0.2822, 0.2951) and the color gamut of 115.09% NTSC (National Television System Committee) standard. The deviation of the experimental chromatic coordinates is within +/- 0.05 to the D65 standard light source. The proposed white-balance realization approach featured by the aperture adjustable subpixels of a chromatic QDCCF may open up a new route for color reproduction in emerging display technologies.

Automated summary

This paper presents an effective method for achieving white balance in QDCCF displays by defining an asymmetric aperture ratio among the three primary-color subpixels. The experimental results show that the proposed approach can achieve high color gamut and is close to the standard light source.