31–40 of 56 posts
I'm surprised the IEEE editors allowed the word "Introducing" in the title. Vacuum FETs are often a target of the diamond thin-film community. (Diamond has a very interesting electronegativity: Very little energy is required to get an electron out of diamond and into the "vacuum" (usually air.))
Earlier quoted context omitted.
The problem is with carbon in general is it has a band gap 5x larger then Silicon. Which overall (but not entirely) means if you want to build a transistor with Diamond (or graphene) you need to put 5x as much voltage into it. The reason graphene is great for transistors is with its higher band energy its 5x harder for it to soft set itself. So if we pretend todays 11nm transistors have a 1% chance of electron tunnel…
You started by saying 5x voltage, switched to 5x power, and ended with 5x energy. Those are not the same thing. You can have 5x voltage without changing the power or the energy.
That said, except for very few embedded applications, computers today operate on a voltage that's much bigger than the silicon band gap. I'm not convinced it'd be a problem.
Would a guitar amp built with these sound like a tube amp?
You can get the correct vacuum tube-like amplification from a computer today, it's just that tubes are still cheaper. A/D converters and first stage linear amplifiers are only getting cheaper (even at this, post Moore's law era), thus it's only a matter of time before computers retire valves on yet another application.
EDIT: Also, tunnel devices have a completely different behavior from macroscopic valves. They are very non-linear, what makes them great at digital applications, but horrible sound amplifiers.
Regarding the opening anecdote - some have suggested the Soviets used vacuum tubes so that their planes would survive the electromagnetic pulse from a nuclear explosion.
There's a middle ground where an EMP would be strong enough to fry a bipolar transistor, but weak enough to fry a tube. I don't know how significative that is for military strategy, but the automatic answer of "transistors can't handle EMP" isn't completely right.
Earlier quoted context omitted.
According to the article, if the device is small enough it doesn't require helium or a vacuum.
"And we’ll have to devise proper packaging methods for these 1-atmosphere, helium-filled devices." Actually it does require helium, but no vacuum.
Earlier quoted context omitted.
According to the article, if the device is small enough it doesn't require helium or a vacuum.
"And we’ll have to devise proper packaging methods for these 1-atmosphere, helium-filled devices." Actually it does require helium, but no vacuum.
It doesn't require helium; helium is just a bit better.
Earlier quoted context omitted.
Well, let's see, a modern chips die size is on the order of 300mm^2. Let's be generous (I think) and call it 5mm thick. A single helium canister can contain around 300 cubic feet of helium [1]. Those are nasty units to work with by hand, but https://www.google.com/search?q=%28300+cubic+feet%29+%2F+%28... suggests one such cylinder would be enough for 5.5 million new chips, assuming the entire chip was just helium. Yo…
300mm^2 * 5mm = 1.5 milliliters 24k Gold is 42$/gram, 1 gram is 0.052 milliliters. So, 42 / .052 * 1.5 = 1,211$. Note: The important parts are not 5mm thick etc, but gold is rather expensive by volume.
Would a guitar amp built with these sound like a tube amp?
I'd bet computers will be emulating the sound of vacuum tubes way before any of those things get into market. You can get the correct vacuum tube-like amplification from a computer today, it's just that tubes are still cheaper. A/D converters and first stage linear amplifiers are only getting cheaper (even at this, post Moore's law era), thus it's only a matter of time before computers retire valves on yet another ap…
Earlier quoted context omitted.
I'd bet computers will be emulating the sound of vacuum tubes way before any of those things get into market. You can get the correct vacuum tube-like amplification from a computer today, it's just that tubes are still cheaper. A/D converters and first stage linear amplifiers are only getting cheaper (even at this, post Moore's law era), thus it's only a matter of time before computers retire valves on yet another ap…
They already do. Check out Line6.com
I'm surprised the IEEE editors allowed the word "Introducing" in the title. Vacuum FETs are often a target of the diamond thin-film community. (Diamond has a very interesting electronegativity: Very little energy is required to get an electron out of diamond and into the "vacuum" (usually air.))
The problem is with carbon in general is it has a band gap 5x larger then Silicon. Which overall (but not entirely) means if you want to build a transistor with Diamond (or graphene) you need to put 5x as much voltage into it. The reason graphene is great for transistors is with its higher band energy its 5x harder for it to soft set itself. So if we pretend todays 11nm transistors have a 1% chance of electron tunnel…
The band gap is not a function of the element alone, but mainly of the crystal structure. Different allotropes of carbon have vastly different band structures.
Diamond has a high band gap, as you mentioned. But Graphene has none, and that is one of the major obstacles of the material.