By applying the first principles calculations combined with density functional theory (DFT), this study explored the optical properties, electronic structure, and structure stability of triangular borophene decorated ...By applying the first principles calculations combined with density functional theory (DFT), this study explored the optical properties, electronic structure, and structure stability of triangular borophene decorated chemically, B3X (X=F, Cl) in a systematical manner. As revealed from the results of formation energy, phonon dispersion, and molecular dynamics simulation study, all the borophene decorated chemically were superior and able to be fabricated. In the present study, triangular borophene was reported to be converted into Dirac-like materials when functionalized by F and Cl exhibiting narrow direct band gaps as 0.19 eV and 0.17 eV, separately. Significant light absorption was assessed in the visible light and ultraviolet region. According the mentioned findings, these two-dimensional (2D) materials show large and wide promising applications for future nanoelectronics and optoelectronics.展开更多
基于第一性原理计算方法,设计出了一种新型二维半导体材料TiO2,并进一步研究了其结构稳定性,电子结构,载流子迁移率和光学性质等.二维TiO2的形成能、声子谱、分子动力学、弹性常数表明,二维TiO2具有较好的动力学,热力学和机械稳定性,具...基于第一性原理计算方法,设计出了一种新型二维半导体材料TiO2,并进一步研究了其结构稳定性,电子结构,载流子迁移率和光学性质等.二维TiO2的形成能、声子谱、分子动力学、弹性常数表明,二维TiO2具有较好的动力学,热力学和机械稳定性,具备实验制备的条件,且能够稳定存在于常温条件下.电子结构分析表明,二维TiO2是一种间接带隙半导体,在GGA+PBE和HSE06算法下的能隙分别为1.19 e V和2.76 e V,其价带顶和导带底能级分别由Ti-3d和Ti-4s态电子构成, O原子的电子态在费米能级附近贡献很小,主要分布在深处能级.载流子迁移率显示,二维TiO2的迁移率比单层Mo S2要小,其电子和空穴迁移率分别为31.09和36.29 cm2·V–1·s–1.由于空穴迁移率和电子迁移率的各向异性,电子-空穴复合率较低,使得单层TiO2的使用寿命更长,光催化活性更好.在应变调控下,二维TiO2的能隙发生明显响应,以适用于各种半导体器件的需要.半导体的带边势和光学性质显示,在–5%-2%单/双轴应变下,二维TiO2能够光裂水制H2,在–5%-5%单/双轴应变下,能够光裂水制O2, H2O2和O3等.此外,二维TiO2对可见光和紫外光具有较高的吸收系数,说明其在未来光电子器件和光催化材料领域有着潜在的应用前景.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant No.11947006)the Cultivating Project for Young Scholar at Hubei University of Medicine,China(Grant No.2018QDJZR22).
文摘By applying the first principles calculations combined with density functional theory (DFT), this study explored the optical properties, electronic structure, and structure stability of triangular borophene decorated chemically, B3X (X=F, Cl) in a systematical manner. As revealed from the results of formation energy, phonon dispersion, and molecular dynamics simulation study, all the borophene decorated chemically were superior and able to be fabricated. In the present study, triangular borophene was reported to be converted into Dirac-like materials when functionalized by F and Cl exhibiting narrow direct band gaps as 0.19 eV and 0.17 eV, separately. Significant light absorption was assessed in the visible light and ultraviolet region. According the mentioned findings, these two-dimensional (2D) materials show large and wide promising applications for future nanoelectronics and optoelectronics.
文摘基于第一性原理计算方法,设计出了一种新型二维半导体材料TiO2,并进一步研究了其结构稳定性,电子结构,载流子迁移率和光学性质等.二维TiO2的形成能、声子谱、分子动力学、弹性常数表明,二维TiO2具有较好的动力学,热力学和机械稳定性,具备实验制备的条件,且能够稳定存在于常温条件下.电子结构分析表明,二维TiO2是一种间接带隙半导体,在GGA+PBE和HSE06算法下的能隙分别为1.19 e V和2.76 e V,其价带顶和导带底能级分别由Ti-3d和Ti-4s态电子构成, O原子的电子态在费米能级附近贡献很小,主要分布在深处能级.载流子迁移率显示,二维TiO2的迁移率比单层Mo S2要小,其电子和空穴迁移率分别为31.09和36.29 cm2·V–1·s–1.由于空穴迁移率和电子迁移率的各向异性,电子-空穴复合率较低,使得单层TiO2的使用寿命更长,光催化活性更好.在应变调控下,二维TiO2的能隙发生明显响应,以适用于各种半导体器件的需要.半导体的带边势和光学性质显示,在–5%-2%单/双轴应变下,二维TiO2能够光裂水制H2,在–5%-5%单/双轴应变下,能够光裂水制O2, H2O2和O3等.此外,二维TiO2对可见光和紫外光具有较高的吸收系数,说明其在未来光电子器件和光催化材料领域有着潜在的应用前景.
