Experimental Research On Mechanical Properties Of Black Phosphorus And Copper Phthalocyanine Based On Atomic Force Microscope

Black phosphorus is considered to be a promising material in the next generation of electronic devices after graphene because of its unique structure and excellent properties,as well as its direct bandgap that can vary with thickness.Also as a nanomaterial,copper phthalocyanine’s structure and energy level determines its many excellent optical and electrical properties,and its layered crystal structure makes the copper phthalocyanine have unparalleled advantages in exploring the new elastic modulus test theory model.Therefore,the research of the mechanical properties of black phosphorus and copper phthalocyanine at nanometer scale is of great significance for its future application in micro/nano electromechanical systems(M/NEMS).The research status at home and abroad were summarized about the testing methods of mechanical properties of thin film used in the micro-nano scale in recent years.Formulas of the nanoindentation and the three-point bending theory model based on the elastic theory of Trichenko which suitable for these experiments were derived,Then,some test platform were constracted based on an atomic force microscope and black phosphorus film was prepared by mechanical stripping method.Nanowires of copper phthalocyanine were prepared by vacuum deposition method and transfer method.The position of the target samples was determined by optical microscope.Raman spectroscopy and atomic force microscopy were used to characterize the number of layers and size of the sample.While measuring its mechanical properties,to explore the impact of test conditions on the target parameters.When the elastic modulus of black phosphorus was studied,it was found that there was almost no effect on the experimental results in the loading speed’s range of 0-20μm/s.When the load was from 2nN increased to 10nN,the value increased by about 35%.When the nano-frictional properties of the black phosphorus film were studied,it was found that the wrinkled effect caused the friction coefficient of four layers of black phosphorus was smaller than that of the two-layer black phosphorus.And the friction force increased linearly with the increase of the load and the logarithm of the scanning velocity.Linked pleat atomic structure and the anisotropy of the stiffness of black phosphorus made the friction of the two layers of black phosphorus and the body black phosphorus all show a 180° periodic change.When the normal load was 2μN,the black phosphorus film was lacerated two layers.As the load increased,wear exacerbated,and black phosphorus was completely pierced until load became 20μN.In the study of the elastic modulus of copper phthalocyanine,when the diameter of the nanowires was less than 200nm,the elastic modulus increased rapidly with the diameter,that was,with the "positive" trend size effect.When the temperature changes from 293K to 343K,the copper phthalocyanine nanobelts’ elastic modulus decreased from 2.82GPa to 1.90GPa.