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<SpeedEvil>
What do you want GaN for?
<SpeedEvil>
Bulk GaN may be nearly trivial
<SpeedEvil>
Semiconductorarily usefully pure may well not be
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<Noxz>
SpeedEvil, photodiode stuffs
<Noxz>
I was looking initially at just AlN, but that was before I knew what a quantum well was
<SpeedEvil>
That needs to be quite pure
<Noxz>
the AlN I can get is pure enough
<Noxz>
and if I can get pure Ga, and Ammonia, then I should be fine making it myself
<Noxz>
doesnt appear difficult
<Noxz>
bbiab, dog walk time
<SpeedEvil>
What do you mean by 'pure enough' - often ppb impurities matter
<Noxz>
but yeah, my orig idea was simply to use a monolayer/bulk of AlN for my photodiode based electron gun, but that likely wont work as much as I once thought it would
<Noxz>
k, bbiab
<Noxz>
the AlN would be froma place that give high purity metal powders, and some of their grades are fr semiconductor... so that should be fine
<SpeedEvil>
nanotubes are inexpensive
<SpeedEvil>
for that quantity anyway
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<Noxz>
nanotubes?
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<SpeedEvil>
They are useful for some classes of electron gun
<SpeedEvil>
I don't know what you're doing
<Noxz>
my goal is e-beam lithography, so I want to be able to switch it on/off quickly.. and tungsten thermionic wire will not do
<SpeedEvil>
err - why not?
<SpeedEvil>
grids are a thing
<Noxz>
grid?
<Noxz>
I dont want to try to switch the HV on/off, nor bend the beam to the side to turn off.. plus I just like the idea of using the photoelectric effect to load up a thing with electrons that eventually get ejected in a vacuum
<Noxz>
and I've give it enough of my time already that I want to go down that route :)
<Noxz>
so, that would actually be the Wehnelt lense/cylinder in a 'standard' electron gun (which was going to be a component in mine as well)
<Noxz>
so, you would actually change from slightly more negative than the thermionic to slightly positive to have the electrons collect onto it vs being repelled... hrmm, interesting control mechanism
<Noxz>
that way the W wire still stays hot and emitting electrons during the 'off' period
<Noxz>
I still want to go after making a photodiode based one, as it seems it may last longer than W based, amongst other reasons
<Noxz>
I will have to use Tungsten initially
<Noxz>
or similarly available mechanisms
<Noxz>
The logic here is still switching something in the kilovolt range by a few hundred volts difference (or simply switching which rail the lense is then tied to, part of the accelerator stack is easy enough to tap into).. versus switching/modulating a source laser
* Noxz
shrugs
<Noxz>
"perationally, one can always increase the negative bias until the emitting area is totally "pinched", with total emission current equal to 0"
<Noxz>
or go even more negative I suppose, which is a different mechanism
<Noxz>
so simply no electrons will boil off
<Noxz>
kthxbye
<sync>
the grid is not at a very high potential
<Noxz>
relative to what
<Noxz>
relative to the pinch voltage? to the thermoionic wire?