Quantum Dots Photoresist for Direct Photolithography Patterning

Quantum dots (QDs) have become the most valuable luminescent materials due to their excellent optical properties, such as high color purity, high photoluminescence quantum yield (PLQY), and tunable luminescence spectra. QDs-based display devices have been used commercially and have shown outstanding advantages such as wide color gamut, high brightness, etc. However, for high-end displays such as micro-light-emitting diodes (Micro-LED), fine precise patterning of QDs is still a prerequisite and key challenge. Recently, direct photolithography, a method based on photochemical reactions of QDs photoresist (QDPR), has been considered as the most potential patterning technology to achieve high resolution and high-throughput. This review focuses on the recent progress of QDPR from the point of view of different photochemical reaction mechanisms: starting the monomer polymerization, followed by the ligand crosslinking or decomposition, and eventually introducing crosslinking additives. Furthermore, a comprehensive overview of the current applications of QDPR in displays is provided based on the different types of LED devices. Finally, existing problems in QDs direct photolithography are discussed, along with possible reasons and solutions. This review is expected to accelerate the development of direct photolithography patterning method and provide general guidance for the further design of QDPR for high-end displays.