Here,we propose a method to determine the thickness of the most common transition metal dichalcogenides (TMDCs) placed on the surface of transparent stamps,used for the deterministic placement of two-dimensional mater...Here,we propose a method to determine the thickness of the most common transition metal dichalcogenides (TMDCs) placed on the surface of transparent stamps,used for the deterministic placement of two-dimensional materials,by analyzing the red,green and blue channels of transmission-mode optical microscopy images of the samples.In particular,the blue channel transmittance shows a large and monotonic thickness dependence,making it a very convenient probe of the flake thickness.The method proves to be robust given the small flake-to-flake variation and the insensitivity to doping changes of MoS2.We also tested the method for MoSe2,WS2 and WSe2.These results provide a reference guide to identify the number of layers of this family of materials on transparent substrates only using optical microscopy.展开更多
文摘Here,we propose a method to determine the thickness of the most common transition metal dichalcogenides (TMDCs) placed on the surface of transparent stamps,used for the deterministic placement of two-dimensional materials,by analyzing the red,green and blue channels of transmission-mode optical microscopy images of the samples.In particular,the blue channel transmittance shows a large and monotonic thickness dependence,making it a very convenient probe of the flake thickness.The method proves to be robust given the small flake-to-flake variation and the insensitivity to doping changes of MoS2.We also tested the method for MoSe2,WS2 and WSe2.These results provide a reference guide to identify the number of layers of this family of materials on transparent substrates only using optical microscopy.
