Nanoporous Silicon-Assisted Patterning of Monolayer MoS 2 with Thermally Controlled Porosity: A Scalable Method for Diverse Applications

© 2018 American Chemical Society. Nanoscale pore formation on chemical vapor deposition grown monolayer MoS2 is achieved using oxygen plasma etching through a nanoporous silicon mask, creating round pores of â70 nm in diameter. The microscale areas with high porosity were successfully patterned via the usage of silicon masks. Thermal annealing in air after the pore formation in the monolayers results in the gradual enlargement of the pores, providing an effective method of controlling edge-to-area ratio of MoS2 crystals. The photoluminescence of the nanoporous MoS2 exhibits rapid increase and blue-shift due to facile p-doping during the thermal annealing process compared to pristine MoS2. This method of fabricating porous transition metal dichalcogenide layers with controlled edge densities presents opportunities in various applications that require atomically thin nanomaterials with controlled pore density and edge sites, such as filtration, electrocatalysis, and sensing.