Advances in color-converted micro-LED arrays. (16th October 2020)

• Record Type: Journal Article
• Authors: Liang, Kai-Ling; Kuo, Wei-Hung; Shen, Hui-Tang; Yu, Pei-Wen; Fang, Yen-Hsiang; Lin, Chien-Chung
• Is Part Of: Japanese journal of applied physics. Volume 60:Number SA(2021)
• Publication Date: 2020-10-16
• Subjects: micro-LED -- full-color -- quantum dot -- fine-pitch; Physics -- Periodicals; 621.05
• DOI: 10.35848/1347-4065/abba0f
• Languages: English
• ISSNs: 0021-4922

Abstract

Abstract: The development of a full-color micro-display at the Industrial Technology Research Institute (ITRI) was reviewed in this study. The blue micro-display with 960 × 540 pixel arrays and 1984 PPI resolution is demonstrated on a CMOS active matrix addressing circuit. Different methods of fabricating such a micro-panel are developed to overcome the limitation in mass transfer. For the device size ranging from 5–100 micrometers, low-current external quantum efficiency of 10%–14% can be obtained. To achieve a full-color scheme, we adapt color-conversion layer design and use colloidal quantum dots as the illuminating material. A full-color array on a transparent substrate of 170 PPI resolution was demonstrated with a large-area blue LED backlight. The red and green pixels were fabricated by a photolithography process and had a size of 30 μ m. The FWHM of 21 and 28 nm and the quantum yield of 28% and 41% for the green and red pixels, respectively, were measured by a 2D spectroradiometer. With superior color provided by quantum dots, it shows a wide color gamut that can fill 87% of Rec. 2020 color space.