In Situ Synthesis of Perovskite Quantum Dot Photoresist in Polymerizable Solvent for 3D Printing and Anti‐Counterfeiting

Perovskite‐quantum dot (PQD) photoresists exhibit excellent optoelectronic properties and have become key modules for the construction of next‐generation optoelectronic devices, including micro‐LEDs, lasers, and optical anti‐counterfeiting. However, traditional preparation of PQD photoresist requires a lot of solvent, harsh conditions, and a time‐consuming process, which hinders the development of PQDs. Herein, we demonstrate in situ synthesis of CsPbX 3 (X = Br, Cl) PQDs photoresist based on polymerizable monomer tricyclic decane dimethanol diacrylate (TCDDA) for 3D printing. TCDDA not only acts as an eco‐friendly solvent and efficient ligand to synthesize and stabilize the PQDs, but also serves as a functional monomer for photopolymerization to encapsulate the PQDs. The PQD photoresist is suitable for photolithography on different substrates, including metals, inorganic materials, polymers, and even paper. Furthermore, we performed 3D printing of arbitrary 3D objects with the smallest feature size of 17 μm by using the PQD photoresist. As a proof‐of‐concept, we depict the potential application of the PQDs photoresist for optical encryption through the construction of quick response (QR) codes and binary codes. This study provides a versatile method for the synthesis of PQD photoresist, and will pave the way for potential applications in flexible optoelectronic devices and anti‐counterfeiting.