Theoretical Design And Properties Research Of Sb/AlAs And GaTe/CdS Heterostructures

Two-dimensional(2D)materials combine low-dimensional structure,special interface morphology,superior optoelectronic properties,and the coexistence of multiple bonding modes.In order to satisfy the progressing requirement for high-performance devices,predicting and designing novel 2D materials and heterostructures have become a burning focus in materials science.In this article,the electronic properties of Sb/AlAs and Ga Te/Cd S heterostructures have been investigated by the comprehensive first-principles calculations.In-depth analysis of the special interface effects and charge transfer mechanism of the two heterostructures,using modulation methods such as changing stacking,applying electric field and strain to further improve the performance of the heterostructures,so as to analyzing the relevant carrier transport process.Strive to obtain some original and innovative scientific discoveries,and provide scientifically valuable ideas and practical and reliable basis for promoting the development of nanoelectronic and optoelectronic devices.Taking the geometric structures and electronic properties of the Sb/AlAs van der Waals(vd W)heterostructure as the starting point,and combining with the first-principles calculations,we have found that the Sb/AlAs heterostructure has a stable atomic structure and small lattice mismatch.In addition,due to the proper direct-gap and the inherent type-II band alignment,appearing the effective separation of photogenerated electron-hole pairs at the heterointerface,which has numerous optoelectronic properties suitable for use in optoelectronic devices.Furthermore,the heterostructure undergoes indirect-gap to direct-gap transition via modulating interlayer distance.When external electric field is applied,the charge transfer is significantly enhanced at heterointerface,and a semiconductor-metal transition is accomplished.The biaxial strain can induce indirect-direct-indirect transition.Meanwhile,throughout the modulation of tensile and compressive strains,the effective mass of electrons and holes express conspicuous anisotropy.The above results provide valuable theoretical guidance for designing high-quality Sb-based vd W heterostructure,and specify an orientation for high-performance optoelectronic devices.In addition,in view of the favorable structural stability and appropriate lattice mismatch,we adopt Ga Te and Cd S monolayers to construct the high-quality Ga Te/Cd S vd W heterostructure.After the monolayer Ga Te contact with Cd S,appearing the type-II band alignment and the direct-gap of 0.804 e V.The unique interface morphology can rapidly ameliorate the photoexcitation and spatial separation capabilities of carriers.It is worth mentioning that within the appropriate electric field range,the Ga Te/Cd S heterostructure undergoes a transition from indirect-gap to direct-gap,and even occurs the semiconductor to metal transition under the strong critical electric field.Within the elastic limit,the biaxial strain can stimulate the heterostructure to appear a direct-gap to indirect-gap transition until the heterostructure transforms into metallic properties at the large strain intensity,indicating that Ga Te/Cd S heterostructure possesses superior tensile strength and controllable conductivity and transportability.The above results indicate that the Ga Te/Cd S heterostructure will provide the theoretical basis for experimental research,and have enormous application potential in future multifunctional optoelectronic devices.