Se和MoSe_2纳米片的结构和发光性能

以Se粉和MoO_3粉为源材料,利用热丝化学气相沉积在N_2中制备了Se和MoSe_2纳米片.利用场发射扫描电子显微镜、透射电子显微镜、X射线能谱仪、显微Raman光谱仪和X射线光电子谱仪对Se和MoSe_2纳米片的结构和组成进行了系统研究.结果表明:Se粉和M0O_3粉的混合与否直接影响了Se和MoSe_2纳米片的形成和结构;当Se粉和MoO_3粉充分混合时形成Se纳米片,而Se和MoO_3粉分开放置时则形成MoSe_2纳米片.研究发现这是由于Se和MoO_3粉的混合与否使Se和MoO_3在气相中的不同反应所致.对Se和MoSe_2纳米片的发光性能研究表明,它们分别产生了774,783和784 nm的发光峰,不同于单层MoSe_2纳米片的发光性能.这些结果丰富了对二维Se基纳米材料的合成和光学性能的知识,有助于对Se基二维纳米材料的光电器件的研制.

Structures and photoluminescence properties of Se and SeMo2 nanoflakes

Se and MoSe₂ nanoflakes are prepared in N₂ environment by hot filament chemical vapor deposition through using Se and MoO₃ powders as the source materials. The structures and compositions of Se and MoSe₂ nanoflakes are systemically studied by using field emission scanning electron microscope, transmission electron microscope, energy dispersive X-ray spectroscope, micro-Raman spectroscope, and X-ray photoelectron spectroscope. The results indicate that the mixing of the Se and MoO₃ powders directly affects the formations and structures of Se and MoSe₂ nanoflakes. When the Se and MoO₃ powders are fully mixed, the Se nanoflakes are formed, however the MoSe₂ nanoflakes are formed under no mixture of Se and MoO₃ powders. This is due to the fact that different reactions of Se and MoO₃ powders in gas environment with or without mixing the Se and MoO₃ powders are generated. The study of photoluminescence properties indicates that the photoluminescence peaks are generated at about 774, 783 nm and 783, 784 nm for the Se and MoSe₂ nanoflakes, respectively, which are different from the photoluminescence properties of monolayer MoSe₂ nanosheet. These outcomes can enrich our knowledge of the synthesis and optical properties of two-dimensional Se-based nanomaterials and will contribute to the development of optoelectronic devices of two-dimensional Se-based nanomaterials.