Quantum Dot Solids, The 21st Century Silicon Wafer

As a product of the 1970s, I grew up with talk of the Silicon Valley from an early age. I understood what that meant about as much as the adults that bandied this land of fairly-tales about in conversation, but they later learned that the silicon wafer changed everything. That may well turn out to be the case with the quantum dot.

Quantum Dot Solids, The 21st Century Silicon Wafer

Quantum dot solids and full disclosure

If I were writing about Apple’s stock potentially rising to $200 based on an analyst’s note to investors I would feel ethically if not legally bound to disclose any positions I held, be them long or short, I held in the company. By the same token, I feel as though I should make it clear that while I have a working understanding of physics and astronomy it could be argued that I shouldn’t perhaps be writing about either. I would, of course, argue that I believe I have an acumen for science writing and making new discoveries approachable. I’ll let you be the judge, but just know I warned you.

A research group from Cornell University believes that they have found the “new” silicon wafer, or rather, a new building block that will make future generations scoff at silicon based chips. The group believes quantum dot solids, or crystals made from crystals, is the future of electronics.

Led by Tobias Hanrath, associate professor in the Robert Frederick Smith School of Chemical and Biomolecular Engineering, and graduate student Kevin Whitham, the team sees a future where two chemical processes being utilized to build two-dimensional superstructures from nothing more than single-crystal foundations.

Essentially, the two have worked out how to build a larger crystal from nanocrystals, while skipping the “glue”. They are then fused together to form an atomically necessary square lattice-like structure.

As far as a level of perfection, in terms of making the building blocks and connecting them into these superstructures, that is probably as far as you can push it,” Hanrath said, referring to the atomic-scale precision of the process.

With this “perfection”, the team has supplanted existing nanocrystals with a material that is far superior in its light emission and energy absorbent properties. Hence, the suggestion of a new generation of electronic devices.

“Charge transport and localization in atomically coherent quantum dot solids”

The titling of the team’s paper, which was published in this month’s Nature Materials, suggests that we’re suppose to just take them at their word, rather than read their work. “We’re” being the laymen that we are compared to these boffins. You’ll excuse me if I don’t think you would naturally choose a value investing website to learn about quantum dots if you had the scientific chops to read their paper.

The electronic coupling of quantum dots has, apparently, been a significant hurdle in the development of the work that the team has achieved. They have achieved the displacement of a connector molecule (ligand) by manipulating the formation of the crystals meant to be joined. With this, the researchers may have finally achieved a structure whose electronic structure can be controlled.

Whitham, while proud of the team’s achievements, recognizes that more like-minded thinkers are needed to continue on their work.

“I see this paper as sort of a challenge for other researchers to take this to another level,” Whitham said. “This is as far as we know how to push it now, but if someone were to come up with some technology, some chemistry, to provide another leap forward, this is sort of challenging other people to say, ‘How can we do this better?'”

It’s pessimistic at best, but this is the realm of any theoretical physicist (which these two are not). They are essentially accomplishing something without practical applications and  they won’t live long enough to see the gift they gave their colleagues.

“It’s the equivalent of saying, ‘Now we’ve made a really large single-crystal wafer of silicon, and you can do good things with it,'” said Hanrath tongue in cheek when speaking of the work with silicon in the 40s and 50s “That’s the good part, but the potentially bad part of it is, we now have a better understanding that if you wanted to improve on our results, those challenges are going to be really, really difficult.”