Design of Quantum Dot Color Convertors for Inkjet‐Printed Optoelectronic Devices: Violet‐Converted Full Color Mini‐LED

Abstract This study presents a strategy of design and development of inkjet‐printable and UV‐curable quantum dot (QD) polymer‐based inks and color conversion (CC) film for use in optoelectronic devices. At first, the preparation of a QD ink is focused on two key aspects, that are QD chemical compatibility and ink printability. In the hybrid organic–inorganic polymer/QDs system, it must be formulated to a well‐dispersed ink, in which a dispersant additive without negative effect on QDs is introduced to enhance the QD suspension. As the optical density of final dried QD film is one of the most critical concerns in color conversion, QD concentration should be as high as possible in the ink, which increases the ink viscosity. Consequently, a trade‐off between QD concentration and the ink viscosity associated with the ink‐jetting temperature is considered to ensure the ink printability. Finally, the designed QD ink is printed as color conversion film on a mini‐LED panel composed of two violet mini‐chips to produce red and green emissions, while blue emission directly comes from a blue mini‐chip. The final conversion efficiency of QDCC on mini‐LED panel are between 35% and 45%, showing the promising applications in optoelectronic devices.