Improved atomic force microscope cleaning of two-dimensional materials

The surface quality is critical for the properties of ultra-thin, two-dimensional (2D) materials since they lack a distinct surface-bulk difference. Conventional Atomic Force Microscope (AFM) based mechanical cleaning to remove surface contaminants is slow and difficult to optimize, limiting its use. We developed a high-throughput, easy-to-implement mechanical cleaning method using an AFM with modified cantilevers. This modification boosts the cleaning rate from 0.05 µm²/s to 150 µm²/s . This dramatically improved cleaning quality, as demonstrated by sharper photoluminescence (PL) in monolayer WS₂ on h-BN and stronger interlayer PL emission in WS₂/MoS₂ heterostructures. Our results offer a practical path for large-scale, integrated 2D material cleaning.