Breakthrough for Quantum Dot Electronics

Los Alamos Researchers have created fundamental electronic building blocks out of quantum dots This could lead to cheaper and more powerful complex electronic devices that can be fabricated in a chemistry laboratory via simple, solution-based techniques, and offer long-sought components for a host of innovative devices.

Quantum dot electronics could make better printable circuits, flexible displays, lab-on-a-chip diagnostics, wearable devices, medical testing, smart implants, and biometrics.

Colloidal semiconductor nanoparticles can be made with chemistry methods without clean rooms. Due to their small size and unique properties directly controlled by quantum mechanics, these particles are dubbed quantum dots.

A colloidal quantum dot consists of a semiconductor core covered with organic molecules. These properties are attractive for realizing new types of flexible electronic circuits that could be printed onto virtually any surface including plastic, paper, and even human skin. This capability could benefit numerous areas including consumer electronics, security, digital signage and medical diagnostics.

The first quantum dot transistors were demonstrated almost two decades ago. However, integrating complementary n- and p-type devices within the same quantum dot layer remained a long-standing challenge. In addition, most of the efforts in this area have focused on nanocrystals based on lead and cadmium. These elements are highly toxic heavy metals, which greatly limits practical utility of the demonstrated devices.

The new quantum dots are using copper indium selenide (CuInSe2) quantum dots devoid of heavy metals they were able to address both the problem of toxicity and simultaneously achieve straightforward integration of n- and p-transistors in the same quantum dot layer. As a proof of practical utility of the developed approach, they created functional circuits that performed logical operations.

Hyeong Jin Yun, Jaehoon Lim, Jeongkyun Roh, Darren Chi Jin Neo, Matt Law, Victor I. Klimov. Solution-processable integrated CMOS circuits based on colloidal CuInSe2 quantum dots. Nature Communications, 2020; 11 (1) DOI: 10.1038/s41467-020-18932-5

Sources. Los Alamos National lab
Written by Brian Wang,

12 thoughts on “Breakthrough for Quantum Dot Electronics”

  1. I'm still an advocate of the clean room for manufacturing and processing, both for contamination control and the protection of personnel. Having a negative pressure flow bench, ducting potential hazard substances, to a more controllable area, within a clean room is not unreasonable. As far as I know (~2009) they were relatively safe in solution, as this prevented any inhalation hazard. It's possible new safety research makes my experience obsolete.

  2. Do you think these would still be a respiratory hazard if they are kept in solution? I'd think fume hood type environment would be needed but not clean room. Clean room is there to protect the products being manufactured, not the personnel…at least to my understanding. I do see your point though, they are potentially hazardous materials if handled improperly but there are similar concerns with existing materials (metal powders for 3d printing) and no clean room is required.

  3. Thanks for the clarification. I've only seen them on TV and it's hard to guessitmate the dimensions during a quick commercial shot.

  4. My brother uses this for his type 1-isch diabetes (they're not really sure what he has yet, he has a little bit of insulin production left a year after diagnosis which is unusual for type 1, but good insulin sensitivity and he's very thin which isn't the case for type 2; appears to be a quite mild form of type 1).

    I'm not sure we're talking about exactly the same thing, but it's more like a CR2032 battery-sized thing that adheres into place and you insert a lead with a needle type thing, then remove the needle and let the soft led remain in contact with blood so it can monitor blood sugar. You use a matchbook sized device or your phone to pick up signals from it, but the thing you wear is CMOS-battery sized on a square piece of adhesive tape stuff.

  5. This could drive the "wearables" revolution that is just starting. They have come out with wearable blood glucose monitors for diabetics, the looks like about size of a matchbook. Still bulky under clothing, this technology could make such monitors more convenient, cheaper and more widespread. If it really is scalable and works for more than a one shot test.

  6. We used QDs perhaps a decade ago in a research grant attempting to tag certain proteins with certain discretely sized and fluorescing dots. Think diagnostic devices. It had possible future implications, with improvements needed. About the flippant 'just create them in a chemistry lab' spiel. You have to understand there's a severe safety issue with inhaling such small particles which would never dislodge themselves from your lungs. Such activities are best conducted under present cleanroom manufacturing conditions, best approaching locations were we currently manufacture semiconductors.

  7. What is it about printed books that you don't like? Or that you do like that you don't like about ebook readers? Do you want something that looks and operates just like a book, except you can make it display any book, just like an ebook reader?

  8. I would love to see– and this is a long way off, but perhaps this is a step– a replacement for writing paper. Like, a different solution for printed books.

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