The Electromagnetic And Optical Properties Of Stanene And Tin Oxide Film Nanomaterials

All the calculations are performed by means of first-principles calculations based on density-functional theory?DFT? with the projector augmented wave?PAW? method. In our work, we investigate the electronic properties and band structures of two dimensional SnO₂ nanosheets and stanene materials.Firstly, we study on the electronic structure, magnetic properties and optical properties of the 3d TM atom?Cr, Mn, Fe, Ni? doped SnO₂ NSs. Computational results indicate that the pristine SnO₂ NSs is a direct gap semiconductor with nonmagnetic states, and the band gap is 2.75 eV. The Cr, Mn, Fe atom doping can induce 2Bm,-3Bm and 2Bm magnetic moment respectively, while the Ni atom doped Sn O₂ NSs keeps the nonmagnetic states. More interestingly, the Fe doped SnO₂ NSs becomes an indirect gap semiconductor, and the Cr, Mn and Ni atom doping remain the character of direct gap semiconductor. For optical properties, the optical absorption edge shows red shift phenomenon for TM atom?Cr, Mn, Fe or Ni? doped SnO₂ NSs. In addition, the tensity of absorption, reflection and refraction coefficient are enhanced significantly in visible light region, which may be very useful to design the solar cells, photoelectronic devices and photocatalysts.Next, the electronic and magnetic properties of 3d transition metal atoms adsorption on 3×3 stanene are investigated in our paper. The calculated results indicate that the TM adatoms on stanene prefer to be relaxed on a hollow site except V atom. For V, Cr, Mn, Fe, and Co adatoms on stanene, the structures present the character of magnetic properties, which the magnetic moments are mainly supplied by adatoms. The Ni, Cu, and Zn adatoms do not induce magnetic moments. The adsorption of V, Cr, Mn, Fe, and Cu turn the stanene into metal, while Ni and Zn adatoms can open up a narrow band gap. We also find that the Co atom adsorption on stanene displays the character of half-metallic properties. More interestingly, a bipolar magnetic gapless semiconductor is observed on Fe decorated stanene. These findings may have great potential future to design new electrically controllable spintronic devices.Meanwhile, we study on the electronic and magnetic properties of 3d transition metal atoms adsorption on 4×4 stanene. The values of total magnetic moments, local magnetic moments and charge transfer are consistent with the 3d transition metal atoms adsorption on 3×3 stanene. The values prove that our results are credible. In the calculation of strain, we find that the stanene can maintain its properties within the range of 2% strain, and the change of band structure is very regular with the change of strain.In the calculation of stanene nanoribbons, we constructe the armchair and zigzag edge stanene nanoribbons, and calculate the band structures of different stanene nanoribbons width. We find that the stanene nanoribbons are direct bandgap semiconductor for all armchair edge models. And the value of band gap presents irregular change. In zigzag edge stanene nonoribbons, only zigzag2 stanene nanoribbon is semiconductor with nonmagnetic, other five configurations stanene nanoribbons show magnetic metal properties. The magnetic moments are mainly supplied by Sn atom which bonding with hydrogen.In the end, we investigate the electronic properties and band structure of stanene adsorbed on MoS₂. We find that the stanene can be open a large band gap?71.9-76.5m? in MoS₂ substrate for different configurations, and the Dirac cone with a nearly linear band dispersion relationship of stanene can be preserved. Meanwhile, we also find that the band gap of stanene can be effectively tuned by the interlayer spacing and external strain. These findings can provide a direction to design the stanene heterojunction.