The system and methods include direct growth of graphene on diamond and low temperature growth of graphene using a solid carbon source.

Benefits

• Direct growth of graphene on insulating substrate at wafer-scale 
• Order of magnitude increase in breakdown current density reaching up to one thousand times improvement over conventional metal based interconnects

A second gas at a second flow rate and a third gas at a third flow rate is inserted into the chamber to increase the chamber pressure to a second pressure greater than the first pressure. A chamber temperature is increased to a first temperature. The flow of the second gas and the third gas is stopped. The chamber is purged to a third pressure higher than the first pressure and lower than the second pressure. The pressure of the chamber is set at a fourth pressure greater than the first pressure and the third pressure. A fourth gas is inserted into the chamber at a fourth flow rate for a first time.

Benefits

• Optically transparent, CVD deposition of reduced graphene oxide film directly on the glass substrate 
• Wafer-scale synthesis in few mins 
• Pin-hole free deposition 
• Moderate sheet resistance at lower thickness 
• High thermal conductivity than Tin Oxide 

A two-dimensional thin film transistor and a method for manufacturing a two-dimensional thin film transistor includes layering a semiconducting channel material on a substrate, providing a first electrode material on top of the semiconducting channel material, patterning a source metal electrode and a drain metal electrode at opposite ends of the semiconducting channel material from the first electrode material, opening a window between the source metal electrode and the drain metal electrode, removing the first electrode material from the window located above the semiconducting channel material providing a gate dielectric above the semiconducting channel material, and providing a top gate above the gate dielectric, the top gate formed from a second electrode material. The semiconducting channel material is made of tungsten diselenide, the first electrode material and the second electrode material are made of graphene, and the gate dielectric is made of hexagonal boron nitride.

Benefits

• Flexible, transparent high mobility thin film transistor for flat panel display 
• 10 atomic layers thick 
• On/off ratio is as good as current commercial thin-film transistors 

Transparent coatings find numerous applications in modern devices. For example, transparent coatings can be used for coating windshields, air craft windows, cell phone screens, tablet screens, computer screens, weapon heads, field deployed sensors, lasers, light emitting diodes (LEDs), etc. These coatings need to be transparent, scratch resistant, have high hardness, corrosion resistance, and generally provide protection from the environment.

There is also an increasing demand for transparent semi-conductor devices. For example, traditional solar cells are fabricated on silicon which is opaque. Only one surface of such solar cells is available for receiving light and generating electricity therefrom. There is also a demand for other semi-conductor devices such as p-n junction devices, LEDs, other diodes, transistors, etc. Moreover, high power high temperature semi-conductor devices produce a substantial amount of heat which needs to be dissipated for proper operation of the semi-conductor devices. 

The patents’ details generally discuss methods for fabricating transparent films and devices; and in particular methods for fabricating transparent nanocrystalline diamond (NCD) coatings, and transparent NCD devices.

Benefits

• Optically transparent, scratch resistant ultrathin film of diamond on glass for protective applications

Description

A method for coating a substrate comprises producing a plasma ball using a microwave plasma source in the presence of a mixture of gases. The plasma ball has a diameter. The plasma ball is disposed at a first distance from the substrate and the substrate is maintained at a first temperature. The plasma ball is maintained at the first distance from the substrate, and a diamond coating is deposited on the substrate. The diamond coating has a thickness. Furthermore, the diamond coating has an optical transparency of greater than about 80%. The diamond coating can include nanocrystalline diamond. The microwave plasma source can have a frequency of about 915 MHz.

Benefits

• Transparent semiconductor devices with high thermal conductivity

This system was constructed as an alternative for detection of obscured objects and material. Depending on the geometry of the given situation a flat-panel source can be used in tomography, radiography, or tomosynthesis. Furthermore, the unit can be used as a portable electron or X-ray scanner or an integral part of an existing detection system. UNCD field emitters show great field emission output and can be deposited over large areas as the case with carbon nanotube ​“forest” (CNT) cathodes. Furthermore, UNCDs have better mechanical and thermal properties as compared to CNT tips which further extend the lifetime of UNCD based FEA.

Benefits

• Prototype based on nitrogen incorporated ultrananocrystalline diamond film 
• Emission current densities of the order of 6mA/cm² could be obtained at electric fields as low as 10 V/lm to 20V/lm 

The first layer is seeded with nanodiamond particles. The substrate with the first layer disposed thereon is maintained at a first temperature and a first pressure in a mixture of gases which includes nitrogen. The first layer is exposed to a microwave plasma to form a nitrogen doped ultrananocrystalline diamond film on the first layer, which has a percentage of nitrogen in the range of about 0.05 atom % to about 0.5 atom %. The field emitter has about 10¹² to about 10¹⁴ emitting sites per cm². A photocathode can also be formed similarly by forming a nitrogen doped ultrananocrystalline diamond film on a substrate similar to the field emitter, and then hydrogen terminating the film. The photocathode is responsive to near ultraviolet light as well as to visible light.

Benefits

• Prototype planer filed emission based electron source for RF injectors in accelerators 
• At surface gradients 45–65 MV/m, peak currents of 1–80mA were achieved. 
• Good operation at moderate high vacuum (10^-6 Torr)

The cathode and anode are in the form of electroactive sheets separated from each other by a membrane that is permeable to the electrolyte. One or more of the cathode and anode comprises two or more layers of carbon nanotubes, one of which layers includes electrochemically active nanoparticles and/or microparticles disposed therein or deposited on the nanotubes thereof. The majority of the carbon nanotubes in each of the layers are oriented generally parallel to the layers. Optionally, one or more of the layers includes an additional carbon material such as graphene, nanoparticulate diamond, microparticulate diamond, and a combination thereof.

Benefits

• Unique combination of diamond nanoparticles and other carbon materials 
• Improves the ability to remove heat efficiently from the battery system 

Nanocrystalline diamond coatings exhibit stress in nano/micro-electro mechanical systems (MEMS). Doped nanocrstalline diamond coatings exhibit increased stress. A carbide forming metal coating reduces the in-plane stress. In addition, without any metal coating, simply growing UNCD or NCD with thickness in the range of 3-4 micron also reduces in-plane stress significantly. Such coatings can be used in MEMS applications.

Benefits

• Excellent chemical, mechanical and electrical properties, low intrinsic stress gradient 
• Could be applicable in many fields, including bio-medicine, optics, and sensors and actuators for space applications