Fabricating Quantum Dot Color Conversion Layers for Micro-LED-Based Augmented Reality Displays

• Published in: ACS applied optical materials Vol. 2; no. 7; pp. 1303 - 1313
• Main Authors: Lin, Chien-Chung, Liang, Kai-Ling, Chao, Han-Yu, Wu, Chun-I, Lin, Suh fang, Huang, Bo-Ming, Huang, Chun-Wei, Wu, Chung-Chih, Kuo, Wei-Hung, Fang, Yen-Hsiang
• Format: Journal Article
• Language: English
• Published: American Chemical Society 26.07.2024
• Subjects: color gamut; Colloidal quantum dots; microdisplays; micro LEDs; color conversion efficiency; high resolution displays; distributed Bragg reflectors
• ISSN: 2771-9855; 2771-9855
• DOI: 10.1021/acsaom.3c00104

Colloidal quantum dots have attracted much attention for their potential application in the color conversion scheme of next-generation microdisplays. One of the possible methods to pattern these nanoparticles into arrays is to use quantum dot photoresists. We will demonstrate a high-resolution color conversion layer with a 1.5 μm by 4 μm subpixel size and a pixel density exceeding 2000 pixels-per-inch (PPI). The photonic characteristics are analyzed, and the estimated color conversion efficiencies are 9.51% for green and 16.55% for red. A full National Television Standards Committee (NTSC) (gamut coverage: 100%, area ratio: 114%) color gamut is achieved in a 992-PPI microdisplay by adding an optical reflector on the top. Without this reflector, the coverage drops to 82.9%. A comparative study found a steady improvement for the photoresist method over the past decade, and a color conversion layer with an even higher resolution can be expected.