back to article Boffins laser print flexible transistors

Printing transistors is nothing new – silicon fabrication is, after all, essentially a print process – but printing silicon ink onto flexible substrates is usually a problem because there's too much heat for the medium to handle. The difficult step is annealing, as that process turns a silicon ink into the polysilicon that …

  1. John Smith 19 Gold badge
    Unhappy

    No mention of how fast these transistors are

    Odds on bet slooooow.

    The problem with this tech has always been if you use the really low cost methods you end up with really slow transistors. IIRC the record is something like 20Mhz.

    OK so that's a pretty sporty PC, back in the mid to late 80's.

    Now how do you do WiFi, BlueTooth etc with those sorts of frequency?

    1. Grikath

      Re: No mention of how fast these transistors are

      Given that they state that their primary application would be in sensors and the like, MHz range would be good enough.

      Not everything needs a multicore GHz processor to function...

      1. John Smith 19 Gold badge
        Unhappy

        Re: No mention of how fast these transistors are

        "Given that they state that their primary application would be in sensors and the like, MHz range would be good enough."

        True provided you can avoid using any kind of modern high frequency comms protocol.

        People use GHz transmission frequencies because the aerials are much smaller.

    2. Cuddles

      Re: No mention of how fast these transistors are

      From the article:

      "They reckon performance is just fine as well: “thin-film transistors using the laser-printed layer exhibited mobilities as high as those of conventional poly-silicon conductors”, the release notes."

      Sure, it doesn't give a solid number in Hz, but you can't really claim there's no mention of how fast they are when it clearly says their performance is just as good as regular transistors.

      1. John Smith 19 Gold badge
        Unhappy

        Re: No mention of how fast these transistors are

        "Sure, it doesn't give a solid number in Hz, but you can't really claim there's no mention of how fast they are when it clearly says their performance is just as good as regular transistors."

        Wrong again. Mobility is a property that contributes to high speed.

        But size and defect density are just as important and if they are printing those transistors they will be huge relative to those on a chip.

        So to give the same results their materials properties have to be much better to achieve the same result.

    3. Loud Speaker

      Re: No mention of how fast these transistors are

      20 MHz is way faster than early audio transistors though, it will do AM radio, and low budget display screens. It is faster than the logic in early PDP8s. There are loads of uses for transistors other than making Pentiums.

      How do you do wifi? Probably stick a blob on the surface, but a lot of electronics does not need wifi or bluetooth. And for the rest, there is always iStuff.

  2. fortran

    PET or PEN?

    https://en.wikipedia.org/wiki/Polyethylene_terephthalate

    https://en.wikipedia.org/wiki/Polyethylene_naphthalate

  3. earl grey
    Thumb Up

    yes, but

    if you could print this all over the outside of your house for power generation....hmmmm whole house printers...

    1. Tom 7

      Re: yes, but

      My next door farm has just put a barn and if they could reach the 8% efficiency of polysilicon PV of the 1980's by printing this stuff on the sheets the roof is made of he'd be pulling in a good 40kw.

      Now so long as HP dont make the ink he'd be quids in!

  4. Crazy Operations Guy

    Would be nice for rapid prototyping

    Could be useful for printing entire chips on it to test them out at low speed before trying to cut some wafers. Maybe we could start seeing some small start-ups building new architectures to get rid of x86...

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