Ultrahigh Resolution Microdisplay Technologies Based on Color Conversion Technique
Professor Ching-Fuh Lin
Graduate Institute of Photonics and Optoelectronics, National Taiwan University
臺灣大學光電所 林清富教授
Our team has successfully integrated polymer color conversion composite materials with oxide nanoparticles, reducing the aspect ratio of their pixel structures, mitigating color crosstalk effects, and enhancing the quantum efficiency (QY) and conversion efficiency (CE) of the color conversion layer. For a color conversion layer thickness of 3 µm (w/ NPs), the QY and CE for green are 86.3% and 86.0%, respectively, while for red, they are 78.8% and 78.5%, respectively. At a thickness of 2 µm (w/ NPs), the QY and CE for green are 78.9% and 72.3%, respectively, and for red, they are 66.3% and 62.0%, respectively. Additionally, we conducted tests on the color conversion layer for water and oxygen resistance and temperature stability. After 240 hours of testing at 60°C and 90% relative humidity, the conversion efficiency of both green and red color conversion layers with added nanoparticles decreased by less than 1%, demonstrating their durability under normal environmental conditions.
The individual array has been miniaturized to a size of 1.4 μm, and the thickness has been reduced to 2 μm. This provides a resolution of 11548 PPI in monochrome and 5774 PPI in full color, as shown in Figure 1. Further optimization of Micro-LED chips and quantum well characteristics, along with the development of integrated circuitry for display driving, will enable real-time control of Micro-LED display images, leading to the realization of ultra-high-resolution full-color conversion microdisplays in the future.
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Fig. 1. (a) The resolution of 11548 PPI in monochrome of red and green pixel arrays. (b) The resolution of 5774 PPI in monochrome red and green pixel arrays and full color pixel arrays.
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