/diy/ - Do It Yourself

>>1668643
LEDs are about chemistry, not machinery

do you mean LED like, *emitter* that you put constant current DC on and it lights up?

Or do you mean LED flashlight, ground lights, room lights or some useful appliance that uses LED emitters you bought, and you just need to put the rest together?

>>1668643
Look up the history of leds and solid-state diodes ok wikipedia or wherever, you should find that a galena crystal can be made to emit a tiny bit of light when current flows through it from a "cat's whisker".
Would make a neat little science demo, if you could make it visible and have the statmech knowhow to back it up. Even I'm not well-versed on the workings behind a shcottky junction, though you may be able to just explain it as a PN or PIN junction without anybody caring, which isn't too difficult.

>>1668643
LEDs are dirt cheap, I can't imagine why you'd want to try to make your own. It wouldn't even be an impressive feat.

It's just annoying because you'd have to somehow track down the correct semiconductor materials, in the small quantities you want, and some very fine detail work to shape it correctly. Making it larger might make it easier but the power required will be all wonky and you might run into other issues with the size that I don't know enough to comment on.

>>1668682
I assumed that since it didn't have to be tiny it was for a science-fair style demonstration. To be honest an electroluminescent display would be easier to make than an LED out of actual semiconductor.

>>1668643
Hey OP what's this to be used for anyhow?

>>1668662
>do you mean LED like, *emitter* that you put constant current DC on and it lights up?
this
>>1668685
i want to make a baghdad battery and my own diy LED because i want to live off grid and want to make my own stuff and be self sufficient
plus it would just be cool.

Forget it lol. Not possible. LED's are made the same way as integrate circuits lol.

>>1668693
Ignoring the historical falsities at work with regards to the baghdad battery, you'd never get an appreciable amount of light. If you want to live off-grid, you'd be better going the prepper route than the primitive tech route. Little science projects such as this are rarely practical.

>>1668700
the only light in my room now is a led desk lamp and my computer screen. considering ill be living in a tiny home i don't think ill be needing much light.

>>1668702
I don't think you fully appreciate how little light (and how much energy consumption, comparatively) you'll get from your DIY led. Or how little power one of those baghdad batteries will actually produce.

I don't think you've looked into this at all desu.

>>1668693
>i want to make a baghdad battery and my own diy LED because i want to live off grid

nice troll sir.

>>1668704
This. The light emitted by a cat's whisker will be barely visible in a darkroom. Enough to illuminate no more than 10 square mm of area on a book, but certainly not an entire book, nor anywhere near enough to see your floor enough to not trip over your discarded dreams.

How about doing some research, like into how semiconductors are doped with N and P substances in the first place? You won't be able to use silicon remember, since silicon has a forward voltage of 0.7V, and 0.7eV per photon is in the IR range. You'd need gallium arsenide or one of the other more obscure semiconductor materials for making into a visible LED. So you'd need to track down or refine your own semiconductor crystals, which have to be extremely pure to work, and somehow dope them, then somehow connect bond wires to them and seal them in some sort of package.
LEDs are one of those instances where making them bigger doesn't make them any easier to construct. On the contrary, high-power LEDs are almost always made of one or more tiny semiconductor chips, never out of large ones, and I assume there's manufacturing difficulties in there.

Some people out there have actually made their own integrated circuits though, which might be an interesting read even if you don't want to spend a few thousand dollars on the necessary equipment.

>>1668744
so i guess the closest thing i would be able to make myself is an incandescent light bulb

>>1668748
Yes, though a cold-cathode neon or other gas tube may be easier than messing with tungsten to make a delicate filament.
As I said earlier it might be more reasonable to make an electroluminescent light source of some sort. Not sure what phosphors will work, but since your electrodes just consist of a piece of foil and a fine wire mesh it's pretty easy to test if you have a signal generator. Could also make a simple resonant transistor circuit to drive one with an inductor at a sensible frequency in order to ensure you're putting energy into the phosphor.

>>1668643
get a chunk of silicon carbide, attach negative to silicon carbide and positive to a needle. Move the needle around on the SiC until you get a glowing spot.
https://makezine.com/2008/11/19/make-presents-the-led/
you didn't specify that it had to be bright. I suppose it would be more practical to make perovskite based LEDs, but you're gonna whine about having to obtain ITO and a handful of toxic chemicals
/thread

>>1668655
>chemistry
solid-state physics
pleb

I make and research perovskite LEDs.

You might like OLEDs too.

First you need a transparent conductive substrate like ITO on glass. Then dissolve lead bromide in DMSO solvent at a 0.3 molar concentration. Then dissolve cesium bromide with the lead bromide solution at 0.3 molar concentration. Once it is all dissolved, you can spincoat on the ito glass substrate at 2000rpm for 1 min. Put it on a hot plate at 70C for 2 mins. Then apply indium gallium eutectic liquid metal on top of the CsPbBr3 as the second electrode. Apply positive 2.5V to the ITO and ground to InGa. Tada you have a bright green led or lec.

>>1668751
>electroluminescent light source
i think i've decided on this similar to the LimeLite Night Light
pretty sure it uses even less energy than led's do but also makes less light.
i did a bit of research and recently they discovered that some sort of red phosphorus formula makes a white light thats even brighter than usual? Sr[Li2Al2O2N2]:Eu2+, dubbed ‘salon’
i watched a short documentary on the history of this kindof tech that stated a few other formulas and advancements.
https://www.youtube.com/watch?v=HTWCrSgyFfo
so i guess i'll be experimenting with this stuff since it seems the easiest and cheapest to build and such low energy requirements

>>1669336
You could start off with simple phosphors like what's found in highlighter pens, or maybe even white paper. But you will need to feed semi-high frequency AC into them, not DC. Likely at a reasonably high voltage too, but you can do that with impedance matching or resonant circuits.

>>1668643
You must first invent the universe.

>>1668643
You could try to apply d.c. current to a chunk of material some sand paper is made of. It might not technically be a diode. You could try and look up the materials and im sure you wont get havked for looking up stuff thats somehow not cool

>>1668643

>>1668693
>i want to make a baghdad battery and my own diy LED because i want to live off grid
If you just get a higher rated LED and underpower it, its effective useful life will be longer than yours.
>and want to make my own stuff
So build an LED array out of multiple diodes
>and be self sufficient
There's a thousand other skills you need to have like growing crops and animal husbandry before you start worrying about electric light sources.
>plus it would just be cool.
It would be inefficient, not only electrically, but economically, based on your resources, which is stupid. What would be cool is making light out of something you grew, so maybe look into oil lamps and refining oil from something you can produce yourself, such as sunflowers or pigs.

>>1671304
Based

>>1675451
you missed the whole point of the thread