Guorong Chen

Structures and electrical properties of Ag-tetracyanoquinodimethane organometallic nanowires

Ag-tetracyanoquinodimethane (Ag-TCNQ) nanostructures are synthesized using both solution reaction in acetonitrile and a novel vacuum-saturated vapor reaction method. Experiments show that the latter synthesis method produces Ag-TCNQ nanowires with better uniformity and higher aspect ratio. These nanowires, having diameters around 100 nm and lengths about 5 /spl mu/m, could serve as potential building blocks of nanoscale electronics. Nanodevices based on these nanowires are fabricated using the electron-beam lithography technique. Electrical transport study shows reproducible I--V hysteresis with a change in resistance of four orders of magnitude, demonstrating electrical memory effect. This electrical bistability makes Ag-TCNQ nanowires a promising candidate for future applications in ultrahigh-density information storage.

Preparation and electrical/optical bistable property of potassium tetracyanoquinodimethane thin films

Potassium tetracyanoquinodimethane (K(TCNQ)) thin films were prepared using physical vapor deposition combined with solid state chemical replacement reaction. Reversible electrical bistable behavior at or even above room temperature was observed; and, the optical bistable property of K(TCNQ) film was observed.

Silver-tetracyanoquinodimethane (Ag-TCNQ) nanostructures and nanodevice

Ag-TCNQ nanostructures are synthesized by using both solution reaction in acetonitrile and a novel vacuum vapor reaction method. Experiments show the latter synthesis method can produce Ag-TCNQ nanowires with high quality. They have diameters around 100 nm and lengths around 5 /spl mu/m. These nanowires could be potential building blocks for nanoscale electronics. Nanodevices based on these nanowires are fabricated using electron beam lithography technique. Electrical properties are characterized and I-V hysteresis is observed reproducibly, which shows memory effect with electrical switching of four orders on-off ratio. Ag-TCNQ nanowires electrical properties make them promising candidates for future applications as ultra-high density information storage media.

A novel formation method of thin polymer film with densely dispersed organic dye by using vacuum technique

Abstract A novel method of thin film formation of organic materials using a vacuum technique is proposed. An organic dye with a high sublimation pressure is loaded in a crucible along with a thin polymer film. After pumping down, the crucible is sealed, then placed in a constant temperature oven. The vapor of dye dissolves into the polymer film, thus forming a thin dye-containing layer.

Control of Gradient Structure of Dye Dispersed in Polymer Thin Films by Vacuum Spray Method

We prepared thin-film polymers containing structures of dispersed dye using a vacuum spray method. Copper(II) 2,9,16,23-tetra-tert-butyl-29H,31H-phthalocyanine [(t-Bu)4CuPc] and polycarbonate were dissolved in chloroform and sprayed under vacuum onto a hot glass plate. During the growth of the thin films, the deposition of (t-Bu)4CuPc was controlled by varying its concentration in the aspirated solutions. Transmission electron microscopic imaging (TEM) and high-angle annular dark field imaging in scanning transmission electron microscopy (HAADF/STEM) with energy dispersed X-ray spectroscopic analysis (EDS) were carried out to confirm the gradient and bilayer structures of (t-Bu)4CuPc dispersed in thin films in cross section.

Molecular Beam Flux Monitor Using Cold Cathode Discharge Induced Emission Spectroscopy

Cold Cathode discharge induced Emission Spectroscopy (CCES) was developed in order to apply a multiple molecular beam flux monitor for molecular beam epitaxy. The response characteristics of the emission intensity were in proportion to the molecular beam flux intensity under the MBE growth condition. The arsenic atomic emission intensity was satisfactorily, corresponding to the As4 molecular beam pressure. The detectable wavelengths of Al, Ga and As were found to be λ (Al)=309 nm, λ (Ga)=294, 417nm and λ (As)=194nm, which did not interfere with each other. When the growth rate of Al was at 0.1 nm/s, and the CCES had an accuracy of 0.1±0.0023 nm/s. The CCES directly controlled the Ga beam flux. The Ga beam pressure directly reflected the response time of the CCES control.

A new storage material for rewritable blue-light DVD

A category of new photochromatic storage material has been found suitable for rewritable digital video disc (DVD). The ratio of transmissivity before and after the write-in process is 3:1 at /spl lambda/=450 nm (blue) and 2:7 at /spl lambda/=650 nm (red), with a transition time of 2-3 ns. The number of write-erase cycles is about 1,000.