Diamonds cutting environmental impact

Oct 18, 2010 By Takashi Hagiwara

Diamonds are known as a girl's best friend due to their splendid sparkle, but they are also held in very high regard by industrialists, who prize their unmatched density, excellent thermal conduction and other properties.

Exploiting these unique properties is the key to a new kind of semiconductor that researchers hope could be a revolutionary advance in energy-efficient technology.

The artificial diamond super semiconductor is being developed by the Diamond Research Laboratory of the National Institute of Advanced Industrial Science and Technology (AIST) in Japan.

Artificial diamonds are most commonly produced by decomposing in a microwave oven at temperatures of about 1,000 Celsius. This process produces minute flakes of carbon, which pile up like accumulated snow to form a thin layer, or laminate, of diamond.

The AIST team has found a way to accelerate that process, and can efficiently produce diamond laminates measuring 2.3 centimeters square and 0.4 millimeter thick -- a size that ranks alongside the largest artificial diamonds produced.

While diamond has natural insulating qualities, adding minute amounts of boric acid and some other substances during the methane-decomposition process produces a diamond that also acts as an excellent semiconductor.

The resulting substance is described by the AIST team as "the ultimate ," far excelling silicon in terms of and voltage resistance. "Given that artificial diamonds can be produced from carbon, which is obtainable in abundance, the diamond semiconductors we envision would be well suited to ," said Shinichi Shikata, 56, who heads the AIST team. He joined AIST after quitting a managerial post with a diamond-processing company six years ago.

Shikata and his team foresee diamond semiconductors being used in and gas-electric hybrids.

Silicon semiconductors require a cooling system to prevent malfunction due to overheating. This is not true of diamond semiconductors, Shikata said, because of diamonds' heat-transfer efficiency.

The AIST team last year created a prototype semiconductor element measuring 1.6 centimeters square, incorporating a 3-square-millimeter diamond semiconductor.

If about 10 such elements were combined to form one large element, it would be suitable for use in the power control system of a hybrid vehicle, Shikata said.

A hybrid car equipped with such technology would consume about 960 kilowatt hours less per year than a conventional hybrid.

If every hybrid vehicle currently in use worldwide had such a system in place, their collective carbon dioxide emissions would be reduced by about 5 million tons over 40 years, he said.

"Our goal is for diamond elements to be in practical use within 10 to 15 years," he said. "If mass-produced, their production cost would be comparable to that of silicon-based elements."

"We'd like to see diamond semiconductors become commonplace some day, since they would be sure to help realize a low-carbon society," he said.

Shikata's laboratory also has been pursuing research into developing high-performance transistors with artificial diamonds.

By manipulating the elemental composition of the carbon flakes, the resulting artificial diamond's heat conductivity can be increased by 150 percent, and have the ability to latch on to electrons, Shikata said. "We can apply this phenomenon to the production of a high-performance transistor," he said.

Explore further: Liquid helium offers a fascinating new way to make charged molecules

3 /5 (2 votes)
add to favorites email to friend print save as pdf

Related Stories

Hope Diamond's phosphorescence key to fingerprinting

Jan 07, 2008

Shine a white light on the Hope Diamond and it will dazzle you with the brilliance of an amazing blue diamond. Shine an ultraviolet light on the Hope Diamond and the gem will glow red-orange for about five ...

Meteorite yields carbon crystals harder than diamond

Feb 03, 2010

(PhysOrg.com) -- Two new types of ultra-hard carbon crystals have been found by researchers investigating the ureilite class Haverö meteorite that crashed to Earth in Finland in 1971. Ureilite meteorites ...

Diamonds key to a sparkling listening experience

Feb 18, 2005

Music lovers could be in for the ultimate listening experience, thanks to a new range of speakers containing parts made of diamond, writes Marina Murphy in the Chemistry & Industry magazine. The unique properties of diamond ...

Diamond is one tough cookie

Jan 26, 2010

(PhysOrg.com) -- Most people know that diamond is one of the hardest solids on Earth, so strong that it can easily cut through glass and steel. Surprisingly, very little is known about the strength of diamond ...

Researchers to Study Properties of the Hope Diamond

Aug 25, 2005

Since January, scientists from the Naval Research Laboratory's Chemistry Division have been studying the optical properties of the Hope Diamond, at the invitation of the Smithsonian Institution. In collaboration with the ...

Recommended for you

Amino acids key to new gold leaching process

11 hours ago

Curtin University scientists have developed a gold and copper extraction process using an amino acid–hydrogen peroxide system, which could provide an environmentally friendly and cheaper alternative to ...

User comments : 0