Studies On Transport Properties Of Optoelectronic Devices Based On Two-dimensional Layered Black Arsenic And Black Arsenic Phosphorus Alloys

Elemental two-dimensional（2D）materials,represented by graphene,have aroused enthusiasm of condensed matter physics scientists.The black arsenic（b-As）and black phosphorus（b-P）in the main group V have puckered structure,high carrier mobility and layer-dependent electronic band structure making the b-As and b-P promising in the application of electronics and optoelectronics fields.However,the study on b-As and b-P still in the initial stage.There is still no systematic study of their basic physical properties.In this paper,the basic physical properties of b-As and black arsenic-phosphorus alloy（b-As P）are systematically studied,and their applications in optoelectronic devices are discussed.（1）The orientation of low-symmetry b-As crystal prepared by mechanical exfoliation was accurately judged by characterization of crystal structure combined with various optical techniques.We did systematic studies on the optical anisotropy property of b-As.The result shows that the b-As has high absorption coefficient and the absorption coefficients along different crystal orientations had strong anisotropy.We prepared b-As based field effect transistor to investigate the electrical transport anisotropy of b-As.The results proved that the b-As based field effect transistor exhibits typical bipolar transport behavior.The maximum anisotropic ratio of electrical performance parameters appears in the armchair direction.These experimental results provide an important theoretical and experimental basis for the application of black arsenic in the field of multi-functional micro-nano electronic and optoelectronic devices.（2）We did the systematic study 2D b-As P which the stoichiometric ratio of As and P is about 0.084:0.916.The anisotropy of lattice vibration of b-As_0.084P_0.916 was explored,and the results prove that the new alloy has the same low-symmetry crystal structure as b-P and b-As.The b-As_0.084P_0.916 based field effect transistor was prepared to thoroughly study the electrical and photoelectric transport properties of b-As_0.084P_0.916.The transistor shows a typical bipolar transport behavior.In the range of visible light to mid-infrared,the b-As P based photodetector showed good photoresponse ability.We did the thoretical calculation to explain the gain mechanism of as doping.These findings provide a strong scientific basis for the development of b-As_0.084P_0.916 in the fields of high-performance nanoelectronic devices and broadband photodetectors.