High-resolution patterning of colloidal quantum dots via non-destructive, light-driven ligand crosslinking

• Published in: Nature communications Vol. 11; no. 1; pp. 2874 - 9
• Main Authors: Yang, Jeehye, Hahm, Donghyo, Kim, Kyunghwan, Rhee, Seunghyun, Lee, Myeongjae, Kim, Seunghan, Chang, Jun Hyuk, Park, Hye Won, Lim, Jaehoon, Lee, Minkyoung, Kim, Hyeokjun, Bang, Joohee, Ahn, Hyungju, Cho, Jeong Ho, Kwak, Jeonghun, Kim, BongSoo, Lee, Changhee, Bae, Wan Ki, Kang, Moon Sung
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 08.06.2020; Nature Publishing Group; Nature Portfolio
• Subjects: 639/301/357/1017; 639/925/357/1017; 639/925/357/995; Colloids; Crosslinking; Displays; Electroluminescence; Electrons; Ethane; High resolution; Humanities and Social Sciences; Ligands; Light emitting diodes; Microprocessors; multidisciplinary; Photoluminescence; Photons; Pixels; Quantum dots; Quantum efficiency; Science; Science (multidisciplinary); Ultraviolet radiation
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-020-16652-4

Establishing multi-colour patterning technology for colloidal quantum dots is critical for realising high-resolution displays based on the material. Here, we report a solution-based processing method to form patterns of quantum dots using a light-driven ligand crosslinker, ethane-1,2-diyl bis(4-azido-2,3,5,6-tetrafluorobenzoate). The crosslinker with two azide end groups can interlock the ligands of neighbouring quantum dots upon exposure to UV, yielding chemically robust quantum dot films. Exploiting the light-driven crosslinking process, different colour CdSe-based core-shell quantum dots can be photo-patterned; quantum dot patterns of red, green and blue primary colours with a sub-pixel size of 4 μm × 16 μm, corresponding to a resolution of >1400 pixels per inch, are demonstrated. The process is non-destructive, such that photoluminescence and electroluminescence characteristics of quantum dot films are preserved after crosslinking. We demonstrate that red crosslinked quantum dot light-emitting diodes exhibiting an external quantum efficiency as high as 14.6% can be obtained. Designing high-resolution displays based on colloidal quantum dots remains a challenge. Here, the authors demonstrate a photo-patterning method to develop CdSe-based core-shell quantum dots patterns of red, green and blue colours with diameters ranging from 7 to 20 nm and resolution of 1400 pixels per inch.