Ultrasensitive Raman measurements in single living cells are possible through exploiting the effect of surface-enhanced Raman scattering (SERS). Colloidal gold particles (60 nm in size) that are deposited inside cells as “SERS-active nanostructures” result in strongly enhanced Raman signals of the native chemical constituents of the cells. Particularly strong field enhancement can be observed when gold colloidal particles form colloidal clusters. The strongly enhanced Raman signals allow Raman measurements of a single cell in the 400–1800 cm−1 range with 1-μm lateral resolution in relatively short collection times (1 second for one mapping point) using 3–5 mW near-infrared excitation. SERS mapping over a cell monolayer with 1-μm lateral resolution shows different Raman spectra at almost all places, reflecting the very inhomogeneous chemical constitution of the cells. Colloidal gold supported Raman spectroscopy in living cells provides a tool for sensitive and structurally selective detection of native chemicals inside a cell, such as DNA and phenylalanine, and for monitoring their intracellular distributions. This might open up exciting opportunities for cell biology and biomedical studies.

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Impact of atomic layer deposition temperature on HfO2/InGaAs metal-oxide-semiconductor interface properties J. Appl. Phys. 112, 084103 (2012) Method for investigating threshold field of charge injection at electrode/dielectric interfaces by space charge observation Appl. Phys. Lett. 101, 172902 (2012) An accurate characterization of interface-state by deep-level transient spectroscopy for Ge metal-insulatorsemiconductor capacitors with SiO2/GeO2 bilayer passivation J. Appl. Phys. 112, 083707 (2012) Electron transport properties of carbon nanotube-graphene contacts Appl. Phys. Lett. 101, 153501 (2012) Response to "Comment on 'Broadening of metal-oxide-semiconductor admittance characteristics: Measurement, sources, and its effects on interface state density analyses'" [J. Appl. Phys. 112, 076101 (2012) (111)-oriented Ge thin films on insulators are essential for advanced electronics and photovoltaic applications. We investigate Al-induced crystallization of amorphous-Ge films (50-nm thickness) on insulators focusing on the annealing temperature and the diffusion controlling process between Ge and Al. The (111)-orientation fraction of the grown Ge layer reaches as high as 99% by combining the low-temperature annealing (325 C) and the native-oxidized Al (AlO x ) diffusioncontrol layer. Moreover, the transmission electron microscopy reveals the absence of defects on the Ge surface. This (111)-oriented Ge on insulators promises to be the high-quality epitaxial template for various functional materials to achieve next-generation devices. V C 2012 American Institute of Physics. [http://dx

a b s t r a c t a-Axis-oriented undoped n-BaSi 2 epitaxial films were grown on Si(111) substrates by molecular beam epitaxy, and the crystalline quality and grain boundaries were investigated by means of reflection highenergy electron diffraction, X-ray diffraction, and transmission electron microscopy (TEM). The grain size of the BaSi 2 films was estimated to be approximately 0.1-0.3 mm, and straight grain boundaries (GBs) were observed in the plan-view TEM images. Dark-field TEM images under a two-beam diffraction condition showed that these GBs consist mostly of BaSi 2 {011} planes. The diffusion length of minority carriers in nBaSi 2 was found to be approximately 10 mm by an electron-beam-induced current technique.

Micro- and mesoporous carbohydrate-derived functional carbonaceous materials of a near-perfect single crystalline cubic nature were prepared via a low-temperature, sustainable hydrothermal carbonization/soft-templating approach.

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Carbon nanodots are a new and intriguing class of fluorescent carbon nanomaterials and are considered a promising low cost, nontoxic alternative to traditional inorganic quantum dots in applications such as bioimaging, solar cells, photocatalysis, sensors and others. Despite the abundant available literature, a clear formation mechanism for carbon nanodots prepared hydrothermally from biomass precursors along with the origins of the light emission are still under debate. In this paper, we investigate the relationships between the chemical structure and optical properties of carbon nanodots prepared by the hydrothermal treatment of glucose. Our major finding is that the widely reported excitation-dependent emission originates from solvents used to suspend the as-prepared carbon nanodots, while emission from dry samples shows no excitation-dependence. Another important highlight is that the hydrothermal conversion of biomass-derivatives under subcritical conditions leads to a heterogeneous mixture of amorphous-like nanoparticles, carbon onion-type and crystalline carbons composed of at least three different phases. The potential chemical reaction pathways involved in the formation of these hydrothermal carbon products along with a comprehensive structural and optical characterization of these systems is also provided.