Preparation And Physical Properties Of Black Phosphorus Two-dimensional Heterostructure

In recent years,van der Waals?vdW?heterostructures have attracted great attention in the scientific community due to their great potential in future functional electronic and optoelectronic devices.Which made up of two dissimilar two-dimensional materials held together by van der Waals interactions.Unlike conventional semiconductor heterojunctions,it is simple to prepare and has excellent electronic and optoelectronic properties as it provides a superior interface quality without the lattice mismatch problem.By stacking these two-dimensional materials together via van der Waals interactions,various heterostructures can be created with novel electronic and optoelectronic qualities superior to those of the isolated materials.In this thesis,the fabrication of BP/ReS₂ heterojunction devices is realized based on mechanically exfoliated and deterministic transfer method,and the electrical properties and photodetection properties of heterostructure devices are studied.The main works are as follows:1.BP/ReS₂ heterostructures were successfully fabricated by two-dimensional material deterministic transfer technology and micro/nano fabrication technology.The heterostructure devices were characterized by optical microscopy,Raman spectroscopy and atomic force microscopy.2.The basic electrical properties of BP and ReS₂ were studied.The results showed that BP exhibits p-type semiconductor properties,ReS₂ exhibits n-type semiconductor characteristics,and the average field-effect mobility is 158.3 cm²V^-1s^-1 and 4.4 cm²V^-1s^-1,respectively.3.The electrical characteristics of the p-n diode of the BP/ReS₂ heterostructure were studied.The results show that the heterojunction we fabricated was a type-III heterostructure,which exhibits a clear gate-tunable rectifying characteristic similar to that of the conventional p-n junction diode,with a maximum rectification ratio of 21.4.The photodetection characteristics of the BP/ReS₂ heterojunction were studied.When 365 nm UV light was applied without a gate voltage,the BP/ReS₂ heterostructure p–n diode has excellent photoresponsive characteristics with photoresponsivity and photogain of 4120 A/W and 14000,respectively.Moreover,an investigation of various channel lengths yielded the highest photoresponsivity of 11811 A/W for a BP length of1?m.These results suggested vdW 2D materials to be promising for developing advanced heterojunction devices for nano-optoelectronics.