Abstract:
A simple, economical method of producing nanowire arrays is described. The method produces high density arrays having nanowires with diameters below 10 nm and does not require templating, catalysts, or surface pre/post-treatment. The disclosed methods and systems can be used, for example, for optoelectronic devices and photovoltaic cells, Li-ion batteries, chemical/bio sensors and transistors.
Abstract:
Inter-allotropic transformations of carbon are provided using moderate conditions including alternating voltage pulses and modest temperature elevation. By controlling the pulse magnitude, small-diameter single-walled carbon nanotubes are transformed into larger-diameter single-walled carbon nanotubes, multi-walled carbon nanotubes of different morphologies, and multi-layered graphene nanoribbons.
Abstract:
Mechanically flexible and optically transparent thin film solid state supercapacitors are fabricated by assembling nano-engineered carbon electrodes in porous templates. The electrodes have textured graphitic surface films with a morphology of interconnected arrays of complex shapes and porosity. The graphitic films act as both electrode and current collector, and when integrated with solid polymer electrolyte function as thin film supercapacitors. The nanostructured electrode morphology and conform al electrolyte packaging provide enough energy and power density for electronic devices in addition to possessing excellent mechanical flexibility and optical transparency.
Abstract:
An ion detection device has a strip of carbon-based nanomaterial (CNM) film and a chamber enclosing the CNM film. A low bias voltage is applied at the ends of the CNM film strip, and ions present in the chamber are detected by a change in the magnitude of current flowing through the CNM film under the bias. Also provided are methods for fabricating the device, methods for measuring pressure of a gas, and methods for monitoring or quantifying an ionizing radiation using the device.
Abstract:
Mechanically flexible and optically transparent thin film solid state supercapacitors are fabricated by assembling nano-engineered carbon electrodes in porous templates. The electrodes have textured graphitic surface films with a morphology of interconnected arrays of complex shapes and porosity. The graphitic films act as both electrode and current collector, and when integrated with solid polymer electrolyte function as thin film supercapacitors. The nanostructured electrode morphology and conformal electrolyte packaging provide enough energy and power density for electronic devices in addition to possessing excellent mechanical flexibility and optical transparency.
Abstract:
Heterojunctions of single-walled carbon nanotubes and p-doped silicon produce a photocurrent when irradiated with visible light under reverse bias conditions. In optoelectronic devices utilizing the heterojunctions, the output current can be controlled completely by both optical and electrical inputs. The heterojunctions provide a platform for heterogeneous optoelectronic logic elements with high voltage-switchable photocurrent, photo-voltage responsivity, electrical ON/OFF ratio, and optical ON/OFF ratio. The devices are combined to make switches, logic elements, and imaging sensors. An assembly of 250,000 sensor elements on a centimeter-scale wafer is also provided, with each sensor element having a heterojunction of single-walled carbon nanotubes and p-doped silicon, and producing a current dependent on both the optical and the electrical input.