Atomic force microscopy(AFM)and scanning probe lithography can be used for the mechanical treatment of various surfaces,including polymers,metals,and semiconductors.The technique of nanoshaving,in which materials are ...Atomic force microscopy(AFM)and scanning probe lithography can be used for the mechanical treatment of various surfaces,including polymers,metals,and semiconductors.The technique of nanoshaving,in which materials are removed using the AFM tip,is employed in this work to produce nanopatterns of self-assembled monolayers(SAMs)on two-dimensional(2D)materials.The materials used are monolayers of transition metal dichalcogenides(TMDs),namely,MoS_(2)and WS_(2),which are noncovalently functionalized with perylene diimide(PDI),a perylene derivative.The approach involves rastering an AFM probe across the surface at a controlled increased load in ambient conditions.As a result of the strong bond between PDI SAM and TMD,loads in excess of 1|1N are required to pattern the monolayer.Various predefined patterns,including a grating pattern with feature sizes below 250 nm,are demonstrated.Results indicate the high precision of nanoshaving as an accurate and nondestructive lithographic technique for 2D materials.The work functions of shaved heterostructures are also examined using Kelvin probe force microscopy.展开更多
基金Science Foundation Ireland,PI_15/IA/3131,Georg Stefan Duesberg。
文摘Atomic force microscopy(AFM)and scanning probe lithography can be used for the mechanical treatment of various surfaces,including polymers,metals,and semiconductors.The technique of nanoshaving,in which materials are removed using the AFM tip,is employed in this work to produce nanopatterns of self-assembled monolayers(SAMs)on two-dimensional(2D)materials.The materials used are monolayers of transition metal dichalcogenides(TMDs),namely,MoS_(2)and WS_(2),which are noncovalently functionalized with perylene diimide(PDI),a perylene derivative.The approach involves rastering an AFM probe across the surface at a controlled increased load in ambient conditions.As a result of the strong bond between PDI SAM and TMD,loads in excess of 1|1N are required to pattern the monolayer.Various predefined patterns,including a grating pattern with feature sizes below 250 nm,are demonstrated.Results indicate the high precision of nanoshaving as an accurate and nondestructive lithographic technique for 2D materials.The work functions of shaved heterostructures are also examined using Kelvin probe force microscopy.
