Non-Destructive Ligand Modification of Colloidal Perovskite Nanocrystals via Olefin Metathesis for Direct Optical Lithography

Direct optical lithography is a process wherein precise patterns are formed by utilizing light to induce changes in the solubility of nanocrystals. To achieve effective incorporation of high-resolution pixels within displays, the application of lithography technology is essential, wherein direct optical techniques play a crucial role. Furthermore, direct optical lithography offers the advantage of reducing processing steps and enabling solution compatibility, large-area processing, and versatility with various materials. To enable direct optical lithography, photosensitive properties must be conferred via ligand exchange or the use of additives. However, such ligand modifications and subsequent patterning processes often compromise the optical and electrical properties of nanomaterials, especially in metal halide perovskite nanocrystals (PNCs) due to ionic characteristics. In this study, we address these issues by conducting ligand modification, endowing the ligands with light-sensitive attributes without damaging the pristine PNCs (PNC-P) surface. We achieve modified ligands with two anchoring sites through olefin metathesis reactions and systematically investigate the effects of the modified ligands on the optical properties, colloidal stability, and morphologies of PNCs with modified ligands (PNC-M). Furthermore, we attain high-resolution patterns by utilizing PNC-M possessing photosensitive property through ligand modification, which were not obtained in PNC-P. Our approach of non-destructive ligand modification via olefin metathesis provides a way for more effectively integrating various semiconducting materials into diverse optoelectronic devices.