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We report a facile phase conversion method that can locally convert n-type SnSe2 into p-type SnSe by direct laser irradiation. Raman spectra of SnSe2 flakes before and after laser irradiation confirm the phase conversion of SnSe2 to SnSe. By performing the laser irradiation on SnSe2 flakes at different temperatures, it is found that laser heating effect induces the removal of Se atoms from SnSe2 and results in the phase conversion of SnSe2 to SnSe. Lattice-revolved transmission electron microscope images of SnSe2 flakes before and after laser irradiation further confirm such conversion. By selective laser irradiation on SnSe2 flakes, a pattern with SnSe2/SnSe heteostructures is created. This indicates that the laser induced phase conversion technique has relatively high spatial resolution and enables the creation of micron-sized in-plane p-n junction at predefined region. 相似文献
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利用扫描隧道显微镜可以在单原子层次上对材料进行操纵,改变其结构与特性,实现原子级结构与物性的精准调控.近年来,扫描隧道显微镜原子操纵技术被广泛用于新型低维材料的精准构筑与物性调控.本文主要介绍应用原子操纵技术对低维材料物性调控的最新研究进展,总结了4种主要探针操纵模式:1)探针局域电场模式; 2)调节探针-样品垂直间距模式; 3)无损形态调控模式; 4)可控裁剪刻蚀模式.通过这些探针操纵模式引入局域的电场、磁场、应力场等,实现在单原子层次上对低维材料的电荷密度波、近藤效应、非弹性隧穿效应、马约拉纳束缚态等新奇物性进行精准地调控. 相似文献
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Monodisperse Au-Fe 3 O 4 heterodimeric nanoparticles (NPs) were prepared by injecting precursors into a hot reaction solution.The size of Au and Fe 3 O 4 particles can be controlled by changing the injection temperature.UV-Vis spectra show that the surface plasma resonance band of Au-Fe 3 O 4 heterodimeric NPs was evidently red-shifted compared with the resonance band of Au NPs of similar size.The as-prepared heterodimeric Au-Fe 3 O 4 NPs exhibited superparamagnetic properties at room temperature.The Ag-Fe 3 O 4 heterodimeric NPs were also prepared by this synthetic method simply using AgNO 3 as precursor instead of HAuCl 4.It is indicated that the reported method can be readily extended to the synthesis of other noble metal conjugated heterodimeric NPs. 相似文献
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本文报道恒电位法在 pH为 1 35的Cu2 SO4、SeO2 、In2 (SO4) 3溶液中 ,在Ti电极上电化学沉积制备CuInSe2 纳米薄膜 .研究络合剂柠檬酸和酒石酸对制备CuInSe2 纳米薄膜的影响 .扫描电子显微镜 (SEM )结果表明 ,加入络合剂后 ,电化学沉积的薄膜表面颗粒分布更均匀、致密 .X射线衍射 (XRD)分析显示 ,制备的CuInSe2 薄膜是黄铜矿和闪锌矿相的混和物 ,添加柠檬酸和酒石酸后 ,衍射峰增强 ,晶形变好 .制备的薄膜颗粒尺寸大小在 2 50nm左右 ,造成粒度增大的原因是由于颗粒的团聚作用 . 相似文献
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Influence of reaction parameters on synthesis of high-quality single-layer graphene on Cu using chemical vapor deposition 下载免费PDF全文
Large-area monolayer graphene samples grown on polycrystalline copper foil by thermal chemical vapor deposition with differing CH4 flux and growth time are investigated by Raman spectra, scanning electron microscopy, atomic force microscopy, and scanning tunneling microscopy. The defects, number of layers, and quality of graphene are shown to be controllable through tuning the reaction conditions: ideally to 2–3 sccm CH4 for 30 minutes. 相似文献
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Monodisperse Au-Fe3O4 heterodimeric nanoparticles (NPs) were prepared by injecting precursors into a hot reaction solution. The size of Au and Fe3O4 particles can be controlled by changing the injection temperature. UVis spectra show that the surface plasma resonance band of Au-Fe3O4 heterodimeric NPs was evidently red-shifted compared with the resonance band of Au NPs of similar size. The as-prepared heterodimeric Au-Fe3O4 NPs exhibited superparamagnetic properties at room temperature. The Ag-Fe3O4 heterodimeric NPs were also prepared by this synthetic method simply using AgNO3 as precursor instead of HAuCl4. It is indicated that the reported method can be readily extended to the synthesis of other noble metal conjugated heterodimeric NPs. 相似文献
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Monodispersive CoPt nanopaxticles in sizes of about 2.2 nm axe synthesized by superhydride reduction of COCl2 and PtCl2 in diphenyl ether. The as-prepared nanoparticles show a chemically disordered Al structure and axe superpaxamagnetic. Thermal annealing transforms the Al structure into chemically ordered Llo structure and the particles are ferromagnetic at room temperature. 相似文献
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Organic molecules modified palladium nanowires arrays prepared by high temperature liquid phase reduction 下载免费PDF全文
This paper reports high temperature liquid phase synthesis of Pd nanowires using chemically modified porous anodic aluminium oxide as template. In this synthesis process, oleic acid is used to modify the inner wall of the pores and Pd^2+ complex with oleylamine is filled into the channel of the template. The complex is then reduced to give oleylamine-capped Pd nanowires. This paper suggests that oleic acid can improve the environment of inner wall of the pores, leading to the formation of uniform Pd nanowires. The synthetic process can be extended to make other types of nanowires. 相似文献