Preparation And Characterization Of Two-dimensional Materials?WSe₂,GeSe₂? Nano-films

Nanomaterials have extraordinary optical,thermal,electrical,magnetic,catalytic and superconducting properties because of their quantum size effects,surface and interface effects,and dielectric confinement effects.As one of the most important materials in the 21 st century,nanomaterials play an important role in electronics,energy technology,advanced engineering materials,and catalysis.The two-dimensional materials represented by graphene have a unique two-dimensional layered structure,have special physical properties of quantum size effect,its electronic and optical properties have undergone a very significant change.Therefore,two-dimensional materials have more advantages,such as their flexibility and high transparency.Two-dimensional materials have broad application prospects in areas such as wearable smart devices and flexible memory devices.Due to the special nature of two-dimensional materials,their structure and composition can be adjusted,resulting in a diversity of properties.Two-dimensional materials have also been used to develop innovative applications of photocatalysts,sensors,nanoreactors,and nanocontainers.In this paper,WSe2 nano-films were prepared by magnetron sputtering and vacuum selenization,and Ge Se2 nano-films were prepared by chemical vapor deposition.X-ray diffraction(XRD),scanning electron microscopy(SEM)and vibration sample magnetometer(VSM)were used to characterize the film samples.The main content of the paper is as follows:(1)The WSe2 nano-films were prepared by a two-step method,and the effects of the substrate,tungsten film annealing,and duration of tungsten film sputtering on the structure of the nano-films were investigated.The orientation of the grains on the sapphire substrate is higher.Annealing treatment helps refine the grain size and WSe2 samples with a higher degree of crystal orientation can be obtained.Extending the sputtering time of the tungsten film contributes to the growth of the WSe2 grain,which makes the sample more crystalline.(2)Ge Se2 nano-films were prepared by chemical vapor deposition.The effects of holding temperature and holding time on the structure of Ge Se2 nano-films were studied.The Ge Se2 nano-films obtained at higher temperature were more uniform,the nano-films obtained in high temperature holding for 7 minutes were much more uniform and compact.By testing the magnetic properties of the Ge Se2 nano-films,we have verified the conclusions we have obtained and found that the Ge Se2 nano-film has ferromagnetism,it has potential applications in areas such as memory.