Ze Xiang Shen

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In this work, graphene layers on SiO(2)/Si substrate have been chemically decorated by radio frequency hydrogen plasma. Hydrogen coverage investigation by Raman spectroscopy and micro-X-ray photoelectron spectroscopy characterization demonstrates that the hydrogenation of single layer graphene on SiO(2)/Si substrate is much less feasible than that of(More)
Graphene was deposited on a transparent and flexible substrate, and tensile strain up to approximately 0.8% was loaded by stretching the substrate in one direction. Raman spectra of strained graphene show significant red shifts of 2D and G band (-27.8 and -14.2 cm(-1) per 1% strain, respectively) because of the elongation of the carbon-carbon bonds. This(More)
Graphene has many unique properties which make it an attractive material for fundamental study as well as for potential applications. In this paper, we report the first experimental study of process-induced defects and stress in graphene using Raman spectroscopy and imaging. While defects lead to the observation of defect-related Raman bands, stress causes(More)
The high mortality rate in cancer such as oral squamous cell carcinoma is commonly attributed to the difficulties in detecting the disease at an early treatable stage. In this study, we exploited the ability of gold nanoparticles to undergo coupled surface plasmon resonance and set up strong electric fields when closely-spaced to improve the molecular(More)
Fe3O4 has long been regarded as a promising anode material for lithium ion battery due to its high theoretical capacity, earth abundance, low cost, and nontoxic properties. However, up to now no effective and scalable method has been realized to overcome the bottleneck of poor cyclability and low rate capability. In this article, we report a bottom-up(More)
Contact angle goniometry is conducted for epitaxial graphene on SiC. Although only a single layer of epitaxial graphene exists on SiC, the contact angle drastically changes from 69 degrees on SiC substrates to 92 degrees on graphene. It is found that there is no thickness dependence of the contact angle from the measurements of single-, bi-, and multilayer(More)
Nanoscale gaps in metal films enable strong field enhancements in plasmonic structures. However, the reliable fabrication of ultrasmall gaps (<10 nm) for real applications is still challenging. In this work, we report a method to directly and reliably fabricate sub-10-nm gaps in plasmonic structures without restrictions on pattern design. This method is(More)
Ordered array of Au semishells on TiO(2) spheres with controlled size are prepared by combining the nanosphere self-assembly and atomic layer deposition (ALD). This ordered 2-D structure with designed array of metal nanogaps can be used as an ultrasensitive surface-enhanced Raman scattering (SERS) substrate with high reproducibility and stability. More(More)
Supercapacitor with ultrahigh energy density (e.g., comparable with those of rechargeable batteries) and long cycling ability (>50000 cycles) is attractive for the next-generation energy storage devices. The energy density of carbonaceous material electrodes can be effectively improved by combining with certain metal oxides/hydroxides, but many at the(More)
A simple and one-step method to rapidly synthesize single crystalline ultrathin gold nanowires at room temperature within a few hours has been developed, and the self-assembled ultrathin gold nanowires demonstrated an intriguing application in surface-enhanced Raman scattering (SERS).