On Thu, 03 Oct 2019 14:58:46 +0100, whisky-dave wrote:

On Thursday, 3 October 2019 14:45:38 UTC+1, Commander Kinsey wrote:
On Thu, 03 Oct 2019 14:37:34 +0100, whisky-dave wrote:

On Thursday, 3 October 2019 14:29:30 UTC+1, Commander Kinsey wrote:
Why do LEDs generate heat? I want a technical answer not "because they're inefficient".

That is the technical answer just like why does a wire get hot when curremnt passes through it.

No, the technical answer would explain what part of it has resistance.

Every conductor has resistance apart from perhaps a superconductor.
yuo also have theb curent passing from one type of conductor to another.

I assumed that the layers were so thin, resistance should be minimal. I guess transistors are the same and they get hot. Semiconductors probably have quite a high resistance?

One of those conductors will convert the energy to light and heat.
They won;t create much IR or UV because the material chosen was chosen because it emits the required wavelengh of light and not much eles.

and if it can be overcome by using different materials.

No they have been trying for years and until someone can come up with a magic substance that has zero resistance that is.

Well they've certainly improved the efficiency over the years. The question is how far can they get without using them at absolute zero? Or perhaps even a completely different way of generating light?

And are you sure it's even resistance? It could be some photons are reabsorbed before they escape the LED, generating heat.

No that would be IR 'heat' , and why would photons be re-absorbed anyway ?

Because they might not come out of the LED into the room, but hit another part of it internally.