A method of fabricating a carbon nanotube based device, including forming a trench having a bottom surface and sidewalls on a substrate, selectively depositing a bi-functional compound having two reactive moieties in the trench, wherein a first of the two reactive moieties selectively binds to the bottom surface, converting a second of the two reactive moieties to a diazonium salt; and reacting the diazonium salt with a dispersion of carbon nanotubes to form a carbon nanotube layer bound to the bottom surface of the trench.

Nanoparticle(NP)-decorated carbon nanotube (CNT) ropes used as sensing elements for hydrogen gas (H.sub.2) chemiresistors are described herein. The NP-decorated CNT rope sensors were prepared by dielectrophoretic deposition of a single semiconducting CNT rope followed by the electrodeposition of metal nanoparticles to highly disperse said nanoparticles on the CNT surfaces. The rope sensors produced a relative resistance change 20-30 times larger than what was observed at single, pure Pd nanowires. Thus, the rope sensors improved upon all H.sub.2 sensing metrics (speed, dynamic range, and limit-of-detection) relative to single Pd nanowires.

A carbon nanotube aligned film as well as a preparation method and application thereof are disclosed. The preparation method includes: providing a carbon nanotube dispersion solution comprising a selected carbon nanotube, a polymer as a carbon nanotube dispersing agent and binding to the selected carbon nanotube, an aromatic molecule binding to the selected carbon nanotube and allowing the surface of the selected carbon nanotube to have the same charges and an organic solvent being at least used for cooperating with the rest components of the dispersion solution to form uniform dispersion solution; and introducing a water phase layer to the upper surface of the dispersion solution to form a double-layer liquid phase system, partially or completely inserting a base into the double-layer liquid system, and then pulling out the base so as to form the carbon nanotube aligned film on the surface of the base.

A method of fabricating a carbon nanotube based device, including forming a trench having a bottom surface and sidewalls on a substrate, selectively depositing a bifunctional compound having two reactive moieties in the trench, wherein a first of the two reactive moieties selectively binds to the bottom surface, converting a second of the two reactive moieties to a diazonium salt; and reacting the diazonium salt with a dispersion of carbon nanotubes to form a carbon nanotube layer bound to the bottom surface of the trench.

A solid-liquid-solid phase transformation (SLSPT) approach is used for fabrication of perovskite periodic nanostructures. The pattern on a mold is replicated by perovskite through phase change of perovskite from initially solid state, then to liquid state, and finally to solid state. The LED comprising perovskite periodic nanostructure shows better performance than that with flat perovskite. Further, the perovskite periodic nanostructure from SLSPT can be applied in many optoelectronic devices, such as solar cells, light emitting diodes (LED), laser diodes, transistors, and photodetectors.

A sensing element comprises a transistor having a gate electrode, a source electrode, a gate electrode and a semiconductor nanostructure connecting between the source and the gate electrodes. The semiconductor nanostructure is modified by a functional moiety covalently attached thereto. A voltage source is connected to the gate electrode. A controller controls a gate voltage applied by the voltage source to the gate electrode such as to reverse a redox reaction occurring when the moiety contacts a redox reactive agent.

A soft conductive composite composition can include a soft matrix containing a conductive member that is associated with a bioactive component. The soft matrix can be formed from a silicone composition. The conductive member can be carbon nanotubes in the silicone composition. The carbon nanotubes can have at least two walls and be conductive. Also, the carbon nanotubes can be a mixture of functionalized carbon nanotubes and non-functionalized carbon nanotubes, which mixture can have a ratio of 1:2 to 1:20 w/w of functionalized to non-functionalized carbon nanotubes per gram of the silicone composition. The bioactive component (e.g., enzyme) can be associated with at least a first portion of the carbon nanotubes. A second portion of the carbon nanotubes can be devoid of the bioactive component.

A carbon nanotube aligned film as well as a preparation method and application thereof are disclosed. The preparation method includes: providing a carbon nanotube dispersion solution comprising a selected carbon nanotube, a polymer as a carbon nanotube dispersing agent and binding to the selected carbon nanotube, an aromatic molecule binding to the selected carbon nanotube and allowing the surface of the selected carbon nanotube to have the same charges and an organic solvent being at least used for cooperating with the rest components of the dispersion solution to form uniform dispersion solution; and introducing a water phase layer to the upper surface of the dispersion solution to form a double-layer liquid phase system, partially or completely inserting a base into the double-layer liquid system, and then pulling out the base so as to form the carbon nanotube aligned film on the surface of the base.

A method of fabricating a carbon nanotube based device, including forming a trench having a bottom surface and sidewalls on a substrate, selectively depositing a bi-functional compound having two reactive moieties in the trench, wherein a first of the two reactive moieties selectively binds to the bottom surface, converting a second of the two reactive moieties to a diazonium salt; and reacting the diazonium salt with a dispersion of carbon nanotubes to form a carbon nanotube layer bound to the bottom surface of the trench.

In various embodiments a light emitting fiber is provided as well as articles of manufacture comprising one or more light emitting fibers. In certain embodiments the light emitting fiber comprises a conductive carbon nanotube fiber; an emissive layer surrounding the carbon nanotube fiber; and a conductive outer layer disposed outside the emissive layer. In certain embodiments the light emitting fiber comprises a hole transport layer disposed between the carbon nanotube fiber and the emissive layer. In certain embodiments the light emitting fiber comprise a hole injection layer disposed between the nanotube fiber and the hole transport layer. In certain embodiments the light emitting fiber comprises an electron transport layer and, optionally an electron injection layer.