Electronic Structure And Property Modulation Of Group Ⅴ-based 2D Materials

The various wonders created in the Information Age owe much to the booming development of the semiconductor industry.The innovation in semiconductor technology heavily relies on the advancements in materials science.Since the discovery of graphene,two-dimensional materials have garnered widespread interest among researchers due to their unique structures and diverse properties.As a result,an increasing number of other two-dimensional materials have been discovered.Currently,numerous two-dimensional materials have been predicted through theoretical calculations and successfully synthesized in laboratories.These materials exhibit unique electronic properties and possess a high surface-to-volume ratio,offering broad prospects for applications in physics,materials science,electronic science,and other fields.Currently,the manufacturing of advanced electronic and optoelectronic applications requires new two-dimensional materials with high carrier mobility and sufficient bandgaps.V-group semiconductor materials exhibit acceptable bandgaps and high carrier mobility,making them highly anticipated for optoelectronic applications.With the deepening of theoretical calculations on two-dimensional materials,various new two-dimensional materials and their extraordinary physicochemical properties continue to be discovered.In this paper,we conducted a systematic study on V-group-based two-dimensional materials（V-V,III-V）based on first-principles calculations.The main research contents are as follows:（1）First-principles study of O-functionalized two-dimensional As P monolayers:electronic structure,mechanical,piezoelectric,and optical properties.We utilized density functional theory（DFT）to investigate the optimized geometries,electronic structures,carrier mobility,piezoelectric properties,and optical absorption properties of b-As P monolayer and three O-functionalized systems.Computational predictions showed that both pristine As P and the three O-functionalized monolayers exhibit strong anisotropic effective mass and carrier mobility,with O functionalization further enhancing the electron mobility in the P-SO monolayer.Biaxial strain induced non-monotonic changes in the bandgap of all oxygen-functionalized materials.Moreover,the incorporation of O atoms significantly increased the piezoelectric coefficients d₁₁and d₁₃.Investigation of the electronic and optical properties of monolayer materials indicated that the three O-functionalized b-As P systems（FO,As-SO,and P-SO）hold potential as candidates for optoelectronic and photovoltaic applications.（2）Strain engineering of electronic,mechanical,and optical properties of orthorhombic III-V group monolayers by first principles calculations.We performed first-principles calculations to investigate the effects of strain on the mechanical,electronic,and optical properties of orthorhombic III-V two-dimensional materials（BN,BP,BAs,Al N,Al P,and Ga N）.Our results indicated that all these monolayers exhibit excellent anisotropy in terms of Young’s modulus,shear modulus,and Poisson’s ratio.Uniaxial strain can effectively modulate the bandgap of these monolayers.Optical property studies reveal highly anisotropic optical absorption in all orthorhombic III-V two-dimensional materials.The remarkable anisotropy and tunable electronic,mechanical,and optical properties suggest that orthorhombic III-V monolayers are promising candidates for optoelectronic and photovoltaic applications.（3）The first principle studies the adsorption of gas molecules on orthogonal BN monolayers.We investigated the adsorption properties of BN for six gas molecules:CO,H₂S,NH₃,NO,NO₂,and SO₂.Based on the analysis of DOS and recovery time,we found that orthorhombic phase BN monolayer can be used for the detection of NO and SO₂ gas molecules at room temperature,and it may have reusable characteristics for detecting NO₂ gas molecules at high temperatures.The study of work function and sensitivity indicates that orthorhombic phase BN monolayer is a promising candidate for NO₂ and SO₂ gas molecule sensors.Our work provides a reference for designing high-performance BN-based gas sensors for NO₂ and SO₂,offering potential options for gas sensing applications.