Synthetic Nanomaterial Developed for Semiconductors

Vanadium oxide bronze nanowires, color-enhanced image (Peter Marley, University at Buffalo)

Chemists and physicists at University at Buffalo in New York created a synthetic nanoscale material with properties making it a potential replacement for silicon in electronic components. The team led by chemist Sarbajit Banerjee and physicist Sambandamurthy Ganapathy published its findings in a recent issue of the journal Advanced Functional Materials (paid subscription required).

The Buffalo researchers were seeking a material with the ability to transfer and store data faster than with current semiconductors. Their investigation resulted in a synthetic form of vanadium oxide and lead, known as vanadium oxide bronze, configured as wires about 180 nanometers wide; 1 nanometer equals 1 billionth of a meter.

Tests on the vanadium oxide bronze nanowires revealed the material acted as both a conductor and a resistor, switching states at room temperature from insulators resistant to conducting a current to metals that more readily conduct electricity. “The ability to electrically switch these nanomaterials,” says Ganapathy, “between the on and off state repeatedly and at faster speeds makes them useful for computing.”

The state-toggling property operates through the lead in the material’s crystalline structure that encourages pools of electrons to accumulate. When a current is applied, however, the pools join, allowing electricity to flow freely through them all and transforming the material into a metal.

Another property — and perhaps a limiting factor — of synthetic vanadium oxide bronze is the ability to exhibit this state-switching property only in nanoscale form, a result of having fewer defects than bulk form. “When materials are grown in bulk, there’s a lot of defects in the crystals, and you don’t see these interesting properties,” says Ph.D. student and lead author Peter Marley. “But when you grow them on a nanoscale, you’re left with a more pristine material.”

Another potential limiting factor is unforeseen health and environmental consequences of these nanomaterials, particularly with lead in the chemistry. Nonetheless, says Banerjee, the findings point to a new generation of electronics based on this nanomaterial.

“Silicon computing technology is running up against some fundamental road blocks, including switching speeds,” notes Banerjee. “The voltage-induced phase transition in the material we created provides a way to make that switch at a higher speed.”

Read more:

• Nanotech Process Devised for Graphene Semiconductors
• Nanotech Fabrication Process Developed for Smaller Chips
• Semiconductor Foundation, NSF Fund Nanoelectronics Research
• Virginia Universities Form Nanotech Research Center

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