Direct Photocatalytic Patterning of Colloidal Perovskite Nanocrystals

<b>Abstract:</b><br/>Perovskite nanocrystals (PeNCs) are emerging materials with significant potential for various optoelectronic applications, especially in LED technologies. For their integration into AR/VR displays, precise patterning technologies are crucial [1]. However, current techniques face challenges in fabricating high-resolution PeNC patterns while preserving their unique emissive properties, due to the inherent instability of these materials. To address this challenge, we develop a direct photocatalytic patterning that can completely preserve the optical characteristics of perovskite nanocrystals (PeNCs). Solubility change of PeNCs is achieved mainly by a photoinduced thiol-ene click reaction between surface ligands and a dual-role reagent, pentaerythritol tetrakis(3-mercaptopropionate) (PTMP), where the thiol-ene reaction is enabled at a low light intensity dose (~ 30 mJ cm^-2) by the strong photocatalytic activity of PeNCs. The photochemical reaction mechanism was investigated using various analyses at each patterning step. The PTMP also acts as a defect passivation agent for the PeNCs and even enhances their photoluminescence quantum yield (by ~5%) and photostability. Multicolor patterns of cesium lead halide (CsPbX₃) PeNCs were fabricated with high resolution (&lt;1 mm). Our method is widely applicable to other classes of nanomaterials including colloidal cadmium selenide–based and indium phosphide–based quantum dots and light-emitting polymers; this generality provides a nondestructive and simple way to pattern various functional materials and devices [2].<br/> <br/><b>References</b><br/>[1] Park et al., <i>Advanced Materials Technologies</i> <b>2022</b>, 2201070<br/>[2] Maeng et al., <i>Science Advances</i> <b>2023</b>, 9, eadi6950