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Viruses Enable Carbon Nanotubes to Better Conduct Electrons in Solar Cells

Virus-enabled technique could find commercial application for companies producing dye-sensitized solar cells

1 min read
Viruses Enable Carbon Nanotubes to Better Conduct Electrons in Solar Cells

One of the fundamental problems in using carbon nanotubes (CNTs) for solar cell applications is that you often get a mix of  semi-conducting nanotubes and conducting (metallic) CNTs.

While a couple of years back researchers discovered that adding imperfections to CNTs used in dye-sensitized solar cells helped in their catalytic function, it did not seem to do much for their conductivity, or really make much of a marked effect on their overall efficiency.

But now Angela Belcher and her research associates at MIT, who have been using viruses to improve lithium-ion batteries, have found that they can use viruses to sort out the various nanotubes and create a better material for transporting electrons through it

The research, which was initially published in the journal Nature Nanotechnologydescribes how by the manipulation of the protein sequence of the M13 virus it created a pH switch that attracts the carbon nanotubes to it.

While the research used dye-sensitized solar cells, the researchers believe that the technique could be used with quantum-dot and organic solar cells.

It is the level of improved efficiency that is obtained through this technique that has impressed. It is reported that this method can improve the efficiency of the dye-sensitized solar cells by 30%, bringing their conversion rate to 8 to 10%. Not earth shattering numbers, but an improvement with these types of solar cells. 

In the article cited above, Prashant Kamat, a professor of chemistry and biochemistry at Notre Dame University who has done extensive work on dye-sensitized solar cell, comments, “Dye-sensitized solar cells have already been commercialized in Japan, Korea and Taiwan,” he says. “If the addition of carbon nanotubes via the virus process can improve their efficiency, “the industry is likely to adopt such processes.”

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3D-Stacked CMOS Takes Moore’s Law to New Heights

When transistors can’t get any smaller, the only direction is up

10 min read
An image of stacked squares with yellow flat bars through them.
Emily Cooper
Green

Perhaps the most far-reaching technological achievement over the last 50 years has been the steady march toward ever smaller transistors, fitting them more tightly together, and reducing their power consumption. And yet, ever since the two of us started our careers at Intel more than 20 years ago, we’ve been hearing the alarms that the descent into the infinitesimal was about to end. Yet year after year, brilliant new innovations continue to propel the semiconductor industry further.

Along this journey, we engineers had to change the transistor’s architecture as we continued to scale down area and power consumption while boosting performance. The “planar” transistor designs that took us through the last half of the 20th century gave way to 3D fin-shaped devices by the first half of the 2010s. Now, these too have an end date in sight, with a new gate-all-around (GAA) structure rolling into production soon. But we have to look even further ahead because our ability to scale down even this new transistor architecture, which we call RibbonFET, has its limits.

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