Enhanced control of particle distribution in colloidal lithography for Janus metal-capped nanoparticles

Surface topography plays a critical role in many fields due to its impact on properties such as adhesion, wettability, and light absorption. In biomedicine, photonics, and electronics, surface characteristics are vital for optimal functionality. Colloidal lithography has emerged as one of the key techniques for fabricating surface topographies, offering a cost-effective, high-resolution, and scalable method for creating structured surfaces. However, achieving non-aggregated particles immobilized on surfaces poses significant challenges that are essential for uniformity and precision. This study systematically analyzes factors affecting particle distribution control in colloidal lithography, including particle materials and sizes, solvent type, heating, and surface coating. We successfully reduced particle aggregation, transitioning from clusters where about 3–4 neighboring particles surrounded each particle to a well-dispersed state with particles no longer adhering to each other. We elucidate the specific limitations of each parameter, providing insights into particle distribution and surface fixation processes. As a practical demonstration, we explore the impact of colloidal lithography on the production of Janus metal-capped nanoparticles. Our results show that well-dispersed particles on surfaces facilitate precise and high-quality nanoparticle production. This precision ensures accurate and consistent thick metal deposition on nanoparticles, which is critical for advancing nanotechnology applications. Our findings have impact to the understanding of colloidal lithography and its implications for developing advanced materials that can be used in many technological domains.