Hello, I replicated the experiments of H.J. Round and Oleg Losev, the inventors of the LED and build an LED from a mineral substance myself. If you like, have a look on it, you might also want to try it ;-) http://www.dlip.de/?p=99 Cheers! Michael
Nice idea! I have a big chunk of this stuff lying around (although I could never figure out what it was, now I know) and I'm definitely going to try the LED.
Shouldn't the rear side of an old (maybe destroyed) processor work for such an experiment? I think about those CPUs, where the chip is mounted in flip chip technology without heat spreader. CPU goes LED :-)
I don't think plain Silicon emits visible light.
No, doesnt work! It needs a semiconducting material with electroluminescent properties. Like SiC or SnO. What I really wonder is whether SiC grains from sand paper can be made working. That would allow a much greater audience to replicate the experiment. Is it plain SiC or coated somehow?
Unbelievable! The article made it to hackaday.com! http://hackaday.com/2009/05/07/make-your-own-leds/
oh, nice idea! It seems he smoked the setup pretty badly but it worked. A little more power and he would have had a incandescent lamp...
I tried it, but I can't say I had a lot of success. A picture of my material is attached. It is from a ceramics factory that works with SiC, and it looks like the SiC picture I found on Wikipedia, so it probably is SiC. Can anyone confirm? The conductivity of the nice, big crystals on top is very low, I could only measure a finite resistance at the lower part of the material. When I connected my power supply and traced the material with the needle (a few mm from the connection) I had to crank the voltage to 30 V to get to 10 mA. I do see a tiny light occasionally, but I also see some faint smoke, so what I'm seeing is probably the contact point overheating. I will give it another try tomorrow.
For me it looks like more or less "pure" silicon. Not SiC.
pure silicon is grey, not black. Pure SiC normally is colorless, but normally black because of impurities (technical SiC). I think, these impurities (if not to much) causes the lighting like a LED.
It depends on the material surface properties. As I wrote, I have a few boxes of the stuff and not all crystals work well. The LED effect can easily be distinguished from overheating by the green light. Overheating is orange and the LED orange or green. If it is green it's certainly not overheating. For your material I'd guess that it is not pure enough...
Hi again, I just tried a bigger chunk just like yours. The molten surfaces seem to be ideal. They give much brighter light then the crystal surfaces. And what can make like almost every crytal work: use 30 V, limit the current to 30 mA and attack the negative lead to a fine tip pencil (Feinminenbleistift). When tracing the crystal with that sucess rate is much greater, although there might be a lot of sparks having nothing to do with the LED effect. But typically for the LED effect a larger region lights up green or orange. Like a little crack or so in the crystal. These regions are reproducible and always give the same light in the same place and with the same shape.