scispace - formally typeset
Search or ask a question

Showing papers by "Joshua E. Goldberger published in 2004"


Journal ArticleDOI
TL;DR: In this article, a review highlights the recent advances in the field, using work from this laboratory for illustration, and the understanding of general nanocrystal growth mechanisms serves as the foundation for the rational synthetic control of one-dimensional nanoscale building blocks, novel properties characterization and device fabrication based on nanowire building blocks.
Abstract: ▪ Abstract Semiconductor nanowires and nanotubes exhibit novel electronic and optical properties owing to their unique structural one-dimensionality and possible quantum confinement effects in two dimensions. With a broad selection of compositions and band structures, these one-dimensional semiconductor nanostructures are considered to be the critical components in a wide range of potential nanoscale device applications. To fully exploit these one-dimensional nanostructures, current research has focused on rational synthetic control of one-dimensional nanoscale building blocks, novel properties characterization and device fabrication based on nanowire building blocks, and integration of nanowire elements into complex functional architectures. Significant progress has been made in a few short years. This review highlights the recent advances in the field, using work from this laboratory for illustration. The understanding of general nanocrystal growth mechanisms serves as the foundation for the rational sy...

1,407 citations


Journal ArticleDOI
TL;DR: The use of metal–organic chemical vapour deposition (MOCVD) and appropriate substrate selection is demonstrated to control the crystallographic growth directions of high-density arrays of gallium nitride nanowires with distinct geometric and physical properties.
Abstract: Single-crystalline, one-dimensional semiconductor nanostructures are considered to be one of the critical building blocks for nanoscale optoelectronics1 Elucidation of the vapour–liquid–solid growth mechanism2 has already enabled precise control over nanowire position and size1,3,4,5,6,7,8, yet to date, no reports have demonstrated the ability to choose from different crystallographic growth directions of a nanowire array Control over the nanowire growth direction is extremely desirable, in that anisotropic parameters such as thermal and electrical conductivity, index of refraction, piezoelectric polarization, and bandgap may be used to tune the physical properties of nanowires made from a given material Here we demonstrate the use of metal–organic chemical vapour deposition (MOCVD) and appropriate substrate selection to control the crystallographic growth directions of high-density arrays of gallium nitride nanowires with distinct geometric and physical properties Epitaxial growth of wurtzite gallium nitride on (100) γ-LiAlO2 and (111) MgO single-crystal substrates resulted in the selective growth of nanowires in the orthogonal [110] and [001] directions, exhibiting triangular and hexagonal cross-sections and drastically different optical emission The MOCVD process is entirely compatible with the current GaN thin-film technology, which would lead to easy scale-up and device integration

487 citations


Patent
08 Apr 2004
TL;DR: Fluidic nanotubes as mentioned in this paper have been used for a variety of applications, such as: nanopores, nanocapillary devices, nanoelectrophoretic, DNA sequence detectors, immunosensors, thermoelectric devices, photonic devices, and imaging devices.
Abstract: Fluidic nanotube devices (29) are described in which a hydrophilic, non-carbon nanotube (152), has its ends fluidly coupled to reservoirs (154 and 156). Source and drain contacts (164 and 166) are connected to opposing ends of the nanotube, or within each reservoir near the opening of the nanotube. The passage of molecular species can be sensed by measuring current flow (source-drain, ionic, or combination). The tube interior can be functionalized by joining binding molecules (160) so that different molecular species can be sensed by detecting current changes. The nanotube may be a semiconductor (132), wherein a tubular transistor (130) is formed. A gate electrode (146) can be attached between source (136) and drain (138) to control current flow and ionic flow. By way of example an electrophoretic array embodiment is described, integrating MEMs switches. A variety of applications are described, such as: nanopores, nanocapillary devices, nanoelectrophoretic, DNA sequence detectors, immunosensors, thermoelectric devices, photonic devices, nanoscale fluidic bioseparators, imaging devices, and so forth.

153 citations


Journal ArticleDOI
TL;DR: In this paper, the authors demonstrate a link between orbital ordering, cation ordering and octahedral tilting in polycrystalline perovskites and show that the coordination of the Jahn-Teller distortions of the MnO 6 octahedra takes place on a short-range length scale.

43 citations