The most exciting phrase to hear in science, the one that heralds new discoveries, is not ‘Eureka!’ (I’ve found it!), but ‘That’s funny…’ -Isaac Asimov.

similar to how LED’s were first noticed back in the day

not in parallel?

This phenomenon was reported May 5, 1861, in letters to Michael Faraday:
http://www.lateralscience.co.uk/sic/index.html

Also, many blue and UV LEDs are made from Silicon Carbide.

seems to me two opposite-polarity diodes of any type in series wouldn’t pass current in either direction, so, really? “Series” and not “Parellel”?

props to DarkFader

I noticed a similar thing 40 years ago when I sawed the top off of a TO-5 transistor and reverse biased the base– the die lit up white! I thought it might have been the metallization going incandescent, but nothing melted– so perhaps it was luminescence. There is still much we don’t know about physics… stay curious, my friends!

Needs Jeri’s perforated aluminum electrode

@Rob Wentworth

That is awesome, thanks for the link.

Are you kidding me? This is blackbody radiation. At 24W you have enough probably based on the thermal characteristics of the material to light up the contacts. The Schottky diodes are indeed relevant, and they affect what area gets heated most, but seriously: look at the color. THIS IS BLACKBODY! hackaday, can you use a bit of discretion when calling everything informed?

To be fair, even researchers make this mistake at first–you get really excited that something’s emitting light, and then you look at the spectrum. . .and realize it’s just blackbody.

@threepointone
A video as proof. Not sure how to embed so here are a couple codes. Don’t know if any of them will work.

@grenadier
“Not only that, I used some canned air to chill the LED and it still emitted light, at a different color too.”

I’m not an expert, but doesn’t the fact that the light has a different color at a different temperature indicate that it is indeed black body radiation?

No, chilling an LED changes the color.

This is the kind of “playing around” that makes life long electronics “guru’s.”

This is great, I love this kind of stuff.

A lot of people don’t know they can open the metal can of a common transistor and see it throw off light too in many cases.

I was amazed when my boss (at a electronics R&D place) didn’t know that regular CCD’s were sensitive to IR light (and that a filter is needed to block it).

Cool stuff!!

i did this too a while back, got yellow AND green light from the same crystal using a piece of conducting thread as the contact.
the wavelength emitted depends on the number of hydrogen atoms within the SiC lattice IIRC, as this alters the bandgap.
Interestingly other people have observed negative resistance in SiC (this was in an IEE article) and the procedure to make them requires only a piece of raw silicon, crystal of SiC and a way to heat it up so the silicon diffuses into the SiC and forms a molecule thick barrier which is the tunnel junction.

Another possibility is that it’s actually incandescing, does it say that it isn’t heating? A semiconductor in contact with a metal with produce heat on one end and will cool on the other. This is unlikely but a possibility. The diode scenarios posited seem unfinished at best to be sure though.