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Nanoscale Physics & Devices Laboratory, Institute of Physics, Chinese Academy of Sciences 2012, Volume 7, Number 5 |
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Address No.8 South Street 3, Zhongguancun, Haidian District, Beijing 100190, China
Website http://nano.iphy.ac.cn
Key Contact
Prof. Hongxing Xu
Director of Nanoscale Physics & Devices Laboratory
Tel: +86-10-82648091
Email: hxxu@iphy.ac.cn
Brief History
Formerly known as Beijing Vacuum Physics Laboratory of Chinese Academy of Sciences since 1985, Nanoscale Physics & Devices Laboratory (NPDL) was established in 2001. The mission of NPDL is to construct and study nanomaterials that address the challenges presented by the national research strategy. For more than 20 years, NPDL has been dedicated to the study of fundamental physics related to nanomaterials and their applications in information and energy devices.
Research Foci
Nano-Plasmonics: The field of Plasmonics concerns the manipulation of light at nanometer scale. Its physical basis is the surface plasmon (SP) resonances in metal nanostructures, where SPs are formed by collective oscillations of free electrons in metal. The properties of SP resonance depend strongly on the material and the structure and can be classified into two categories, namely the propagating and the localized SPs. Based on these two different types of SPs, metal nanostructures have shown many fantastic properties, which lead to the applications of plasmonics in the fields of information technology, biological sensing, renewable energy and super-resolution imaging, etc.
Nanomaterials and Nanodevices: The fabrication and application of nanomaterials and nanodevices are one of the most active and important research fields internationally. A promising alternative route to make even smaller functional nano-materials and devices is the autonomous ordering and assembly of atoms and molecules on surfaces that are atomically defined. This approach combines the ease of fabrication with exquisite control on the shape, composition and mesoscale organization of the surface structures formed.
Nano- and Molecular Electronics: Nanoscale and molecular structures possess very different physical properties and allow scientists to explore new quantum phenomena on electron motion, photon propagation and spin properties. It is expected that this research will enable constructing electronic and photon-electronic devices with new functionalities, based on new principles, by using atoms and molecules as building blocks.
Surface Physics and Chemistry: Solid surfaces provide the necessary substrates for nano/molecular structures and devices and can be altered through the adsorption of organic functional molecules or the combination with different hetrostructures in a layered system. The development of scanning tunneling microscopy (STM) techniques has allowed the atomic-scale precision and high energy resolution on surfaces in the study of nanostructures and individual molecules.
Molecular Electronics and Nanodevice Fabrication: As the size of physical systems goes down to nanometer, fantastic quantum effects may emerge due to the interaction between the systems and the environments, such as the confinement of charge carriers on surfaces and interfaces. Our research interests have been focused on understanding the fundamental physics that determines the behaviors related to charge transport in mesoscopic systems, and constructing novel nanostructure devices.
Graphene Nanostructures toward Device Applications: With the aim to fabricate various functional devices, we develop new methods toward controllable growth of graphene and state-of-the-art fabrication of graphene nanostructures. Some devices such as NEMS switching devices, strain sensors and resistive switching memories (RRAM) have been successfully demonstrated using these structures in the research group.
Recent Projects
Nano-Plasmonics: We have discovered that in homogenous medium, the coherent superposition of different waveguide modes on metallic nanowires can generate chiral (left-handed or right-handed) surface plasmons that propagate helically along the nanowire. Plasmon interference has been used to modulate the plasmon propagation in silver-nanowire-based structures. By using quantum dot fluorescence, we have imaged the electric field distributions around the nanowires and found the dependence of the plasmon near-field distribution on the polarizations and phases of the incident laser light. Based on surface plasmon interferences, a complete set of binary logic gates has been realized, and it has been demonstrated that these plasmonic logic gates can be cascaded to realize more complex functions in simple nanowire networks. By using the high vacuum STM and Raman spectroscopy combined system, we have found that the hot electrons generated by surface plasmons on gold tip can induce the photocatalytic reactions for the molecules under the tip.
Nanomaterials and Nanodevices: Fabrication and self-assembly of low dimensional nanomaterials are realized with a variety of physical and chemical techniques, such as CVD, LB, MBE etc. Once the mechanisms that describe the controlling of the self-ordering phenomena are fully understood, the self-assembly and growth processes of nanostructures can be steered to create a wide range of surface nanostructures from metallic, semiconducting and molecular materials.
Nano- and Molecular Electronics: Researches are focused on some very basic scientific problems: tuning of the interactions between particles or functional molecules, precise determination of geometric and electronic structures, accurate measurement of physical properties of nanoparticles and understanding the relationship between geometric structures, electronic structures, and their physical properties. Four probe STM is employed to do the transport properties of low dimensional structures including the organic molecules that react very sensitively to the chemical and electrical environment.
Surface Physics and Chemistry: We employ UHV-MBE together with LTSTM, VTSTM and RTSTM for the investigation of surface structure, electronic structure, and properties at the scale of single atom and molecule. These equipments and techniques also offer the opportunities to manipulate single atom and molecule, probe the induced periodic molecular vibrational and translational motions and investigate the dynamic behavior on surfaces in real time.
Molecular Electronics and Nanodevice Fabrication: We developed a new method for fabricating heterometallic nanogap electrodes that exhibit distinct magnetic properties or work functions, which enables the fabrication of many interesting functional molecule devices such as spin-valve and molecule-size optoelectronic devices. Moreover, DWCNT quantum dot devices with perfect transport properties at room temperature and novel structured DWCNT nanodevices have been constructed. Further investigation of the quantum effects of carbon nanotube devices at low temperature is on schedule.
Graphene Nanostructures toward Device Applications: Using new techniques to fabricate graphene nanostructures with well-defined edge structures and exploring the edge-related new physical phenomenon using optical and electrical spectroscopy. Researchers in this group have developed the first technique for scalable fabrication of graphene nanoribbons with zigzag edges and observed edge-related electron-phonon coupling.