The continuous evolution toward semiconductor technology in the "more-than-Moore" era and rapidly increasing power density of modern electronic devices call for advanced thermal interface materials (TIMs). Here, we report a novel strategy to construct flexible polymer nanocomposite TIMs for advanced thermal management applications. First, aligned polyvinyl alcohol (PVA) supported and interconnected 2D boron nitride nanosheets (BNNSs) composite fiber membranes were fabricated by electrospinning. Then, the nanocomposite TIMs were constructed by rolling the PVA/BNNS composite fiber membranes to form cylinders and subsequently vacuum-assisted impregnation of polydimethylsiloxane (PDMS) into the porous cylinders. The nanocomposite TIMs not only exhibit a superhigh through-plane thermal conductivity enhancement of about 10 times at a low BNNS loading of 15.6 vol % in comparison with the pristine PDMS but also show excellent electrical insulating property (i.e., high volume electrical resistivity). The outstanding thermal management capability of the nanocomposite TIMs was practically confirmed by capturing the surface temperature variations of a working LED chip integrated with the nanocomposite TIMs.

Advances in extreme-ultraviolet (EUV) and X-ray optics are providing powerful new capabilities in high-resolution imaging and trace-element analysis of microscopic specimens, and the potential for fabricating devices of smaller critical dimensions in next-generation integrated circuit lithography. However, achieving the highest resolution with such optics usually requires the illuminating EUV or X-ray beam to be highly monochromatic. It would therefore be highly desirable to have large-field-of-view, sub-100-nm resolution optics that are achromatic to a significant degree, allowing more light to be utilized from broader bandwidth sources such as laser-produced plasmas. Here we report an achromatic Fresnel optical system for EUV or X-ray radiation that combines a Fresnel zone plate with a refractive lens with opposite chromatic aberration. We use the large anomalous dispersion property of the refractive lens material near an absorption edge to make its fabrication practical. The resulting structure can deliver a resolution comparable to that of the Fresnel zone plates that have achieved the highest resolution (25 nm; ref. 3) in the entire electromagnetic spectrum, but with an improvement of two or more orders of magnitude in spectral bandwidth.

Control and acquisition systems for new scanning transmission x-ray microscopes at Advanced Light Source (abstract) Rev. Sci. Instrum. 73, 1591 (2002; 10.1063/1.1448125Simple method for estimating linear attenuation coefficients from x-ray diffraction tomography data Rev. Sci. Instrum. 72, 1918 (2001; 10.1063/1.1344171 2D imaging by X-ray fluorescence microtomography AIP Conf.A third-generation synchrotron radiation source provides enough brilliance to acquire complete tomographic data sets at 100 nm or better resolution in a few minutes. To take advantage of such high-brilliance sources at the Advanced Photon Source, we have constructed a pipelined data acquisition and reconstruction system that combines a fast detector system, high-speed data networks, and massively parallel computers to rapidly acquire the projection data and perform the reconstruction and rendering calculations. With the current setup, a data set can be obtained and reconstructed in tens of minutes. A specialized visualization computer makes rendered three-dimensional ͑3D͒ images available to the beamline users minutes after the data acquisition is completed. This system is capable of examining a large number of samples at sub-m 3D resolution or studying the full 3D structure of a dynamically evolving sample on a 10 min temporal scale. In the near future, we expect to increase the spatial resolution to below 100 nm by using zone-plate x-ray focusing optics and to improve the time resolution by the use of a broadband x-ray monochromator and a faster detector system.

Novel dielectric materials using crosslinkable high-kcopolymers were prepared with high energy density and high efficiency. They were also applied as OFET gate dielectrics to achieve low-voltage operation.

Highly oriented and large-scale ZnO nanorod arrays have been successfully synthesized on zinc foil by a simple, low-temperature, solution-phase approach. In this approach, zinc foil was used not only as a substrate but also as a zinc-ion source for the direct growth of ZnO nanorod arrays. X-ray diffraction (XRD) analysis, high-resolution TEM (HRTEM) images, and selected-area electron diffraction (SAED) patterns indicated that the structure of the ZnO nanorod arrays on the zinc foil substrate was single-crystalline and grown in the [0001] direction with a wurtzite structure. The optical properties of the ZnO nanorod arrays were characterized by UV−vis diffuse reflectance, Raman, and photoluminescence spectroscopies. The photocatalytic activity of the ZnO nanorod arrays was tested by degradation of 4-chlorophenol (4-CP) under UV light irradiation compared to that of a ZnO nanorod film grown on a Ti substrate, indicating that the as-synthesized ZnO nanorod arrays exhibit excellent photocatalytic activity.