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: Provided in one embodiment is a method for operating a photodiode device, which device comprises: at least one layer of an n-doped semiconductor material; two portions of a dielectric material separately disposed over separate regions of the at least one layer of the n-doped semiconductor material; at least one monolayer of a carbon-based material disposed between the two portions of dielectric material and over the at least one layer of the n-doped semiconductor material; two terminal electrodes, each electrode disposed in electrical communication with a respective one of the portions of dielectric material; and a gate electrode in electrical communication with the at least one layer of the n-doped semiconductor material. The method comprises: applying a voltage across the gate electrode and one of the two terminal electrodes; and exposing the photodiode device to electromagnetic radiation.

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.

Abstract: A chemical vapor deposition (CVD) method using a vapor phase catalyst of directly growing aligned carbon nanotubes on a metal surfaces. The method allows for fabrication of carbon nanotube containing structures that exhibit a robust carbon nanotube metal junction without a pre-growth application of solid catalytic materials to the metal surface or the use of solder or adhesives in a multi-step fabrication process.

Abstract: A chemical vapor deposition (CVD) method using a vapor phase catalyst of directly growing aligned carbon nanotubes on a metal surfaces. The method allows for fabrication of carbon nanotube containing structures that exhibit a robust carbon nanotube metal junction without a pre-growth application of solid catalytic materials to the metal surface or the use of solder or adhesives in a multi-step fabrication process.