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Transistors Minus Semiconductors

Iron quantum-dot studded nanotubes
2/9/2016 07:51 PM EST
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R_Colin_Johnson
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Re: Three Terminals
R_Colin_Johnson   2/11/2016 11:29:54 AM
Here is author's answer--he already demonstrated a three-terminal transistor: "We have previously reported on using Au QDs-BNNTs for TFETs using a back gate configuration as in ref 25. You can use the following link for the full paper:
Lee et al, "Room-Temperature Tunneling Behavior of Boron Nitride Nanotubes Functionalized with Gold Quantum Dots," Advanced Materials 25, 2544 (2013).

The purpose of the current work is to demonstrate that Fe QDs-BNNTs is the flexible channels that behave the same as Au QDs-BNNTs in a two-terminal configuration. These Fe QDs-BNNTs can be put down as T-FETs in the future as we demonstrated for Au QDs-BNNTs.

R_Colin_Johnson
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Re: Three Terminals
R_Colin_Johnson   2/11/2016 10:32:02 AM
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I'll querey the authors. Since it was published in a reputable journal there must be an explanation. Stand by.

AKH0
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Re: Three Terminals
AKH0   2/10/2016 5:36:12 PM
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There is no gate here. The paper reads: "our back gate configuration is not ideal for such an investigation where only moderate gate effect was demonstrated25. Therefore we plan to study these topics with an alternative gate configuration for both Fe and Au QDs-BNNTs in the future." I wonder how the authors justify using "transistor" as the title of a paper reporting a 2-terminal device and how a reputable journal is ok with that.  

anon5131637
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Three Terminals
anon5131637   2/10/2016 4:28:07 PM
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How do you construct a three-terminal device out of this?

R_Colin_Johnson
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Re: TFETs Have Zero Leakage
R_Colin_Johnson   2/10/2016 1:35:51 PM
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Here's his justification for being vague: "There are many other factors that determine the mobility, including the properties gate oxide, distance between QDs, etc. I am trying not to speculate a number here before we have the experimental evidence. Stay tune :)"

alex_m1
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Re: TFETs Have Zero Leakage
alex_m1   2/10/2016 12:37:03 PM
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Thanks Colin. Sadly they didn't mention even an order of magnitude estimate on on future carrier mobility , because they are orders of magnitude far from reasonable mobility , so just being "much higher" doesn't mean a lot .

R_Colin_Johnson
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Re: TFETs Have Zero Leakage
R_Colin_Johnson   2/10/2016 12:32:03 PM
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Alex, here is the authors answer to your questioin about disall mobility: "One unique feature of this type of TFET channel is that switching is more efficient at very short channel length due to the smaller self capacitance and tunneling resistance. This is in contrast to the short channel effect in semiconducting FETs. The low mobility and high turn-on voltages in the proof of concept work here are related to the long channel length tested in the STM-TEM holder. We believe that the mobility will be much higher in actual transistors with gate electrodes and shorter channel lengths (10-100nm)."

R_Colin_Johnson
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Re: TFETs Have Zero Leakage
R_Colin_Johnson   2/10/2016 12:08:13 PM
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The only theoretical extrapolation they mentioned was the 0.1 turn-on voltage, but I'll send your question to them and see what they say. Thanks for the careful reading.

alex_m1
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Re: TFETs Have Zero Leakage
alex_m1   2/10/2016 12:05:06 PM
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Interesting find Colin, sound like a great transistor structure . But looking into the article , it has carrier mobility of 3.2*10^-7 which sounds very bad(if i'm undersnading it right) , probably because they choose larger transistors . But how well do they think this will scale down to real transistors ?

R_Colin_Johnson
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TFETs Have Zero Leakage
R_Colin_Johnson   2/10/2016 9:32:43 AM
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Semiconductors are one the way out, if you believe in quantum-tunneling transistors on nanotubes like Michigan Tech. These TFETs are different than others you may have been researching and are still years away from commercialization, but they dream the dream of zero leakage and sub-0.1 volt operation.

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