Why all solar panels are secretly LEDs (and all LEDs are secretly solar panels)

LEDs and solar panels are both made of diodes. A diode is just designed to allow electricity to flow in one direction but because we make them out of semiconductors they can do all these other things.

And here it is as a PDF:

Animations by Dom Burgess. His brilliant channel, Every Think, is here:

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Glenn Watson
Joël van der Loo

[moth.monster]

Resistors can also emit light but only once

[error]

1. electric motor <=> generator
2. mic <=> speaker <=> piezo
3. solar panel <=> diode <=> led

[ZeldagigafanMatthew]

So, should we call solar panels Light Absorbing Diodes (or LADs) instead? I think so.

[positronundervolt]

'You can use a speaker as a microphone.'

Hello, CIA.

[JohnnyX]

I first had that eureka moment when I was sat playing with an LED and was reminded of the 'equal and opposite reaction' law. I thought if LEDs emitted light when a voltage was passed through them, would they create a voltage if light was shone at them. To my amazement this was true as I also connected a volt meter across an LED and shone a bright light at it. It was a few years ago when I did this, and now I have discovered this video and it has made me smile! Thank you! True scientific discovery and learning :)

[jpopelish]

I had a long career as a circuit designer, and several times, with high gain circuits, with diodes, I had to take the light sensitivity of the diodes into account.

[sethsims]

I saw a video by a professor who researches solar cells. He talked about how LEDs get some amount of their energy from the heat of the crystal lattice. He said if you could get the efficiency of the LED high enough (80ish percent of electrical power into light) they would actually act as refrigerators rejecting heat as entropy in the light emitted. He talked about putting such a super LED across the vacuum of a Dewar flask from a high efficiency PV cell to make a heat pump from the inner wall to the outer wall. All this is pretty well known by people who study PV cells and LEDs, but I had no idea and find it super interesting.

[kristopherlee]

I have forgotten so much of my electronic knowledge from the late 80's ...seeing this video makes me want to learn everything again.. Ty

[SteveFrenchWoodNStuff]

I spent over 35 years of my life in electronics; how did I not know this until now? Thanks for another eye-opening, insightful video!

[lucasbhogal]

we just learned that in school, but with this video I understand it

[trippytrev]

I love how you get right to the point and explain it in a way everyone can understand

[tomasdahuabe]

This video gave me the idea to test old film camera shutter speeds for servicing them. I made a really simple device which is just an LED soldered to an input jack connected to an audio interface to my PC and then on the other side of the camera shutter I put a laser pointer pointing to where the LED would be on through the shutter, shoot the camera while recording the "audio" signal and then see the audio clip to check the interval. And it works perfectly :)

[leonmanetana]

This reminds me that the earlier Raspberry2 B models had a single diode that caused the computer to reset when a sufficiently powerful light hit the board. For example, a photo flash... this is why those earlier models were called "camera shy".

Fun stuff.

[QuantumFluxable]

hey Steve, I'm studying electronics and I gotta say, pretty well made video! if you want to look at other "reversable" electromechanics stuff here's a few examples: Peltier-/Seebeck-Effect (voltage creates temperature differential, but temperature differential also creates voltage), Piezo-Effect (voltage -> crystal lattice deforms, crystal lattice deforms -> voltage), or coupled inductors (current in one coil -> voltage in the other, but also it affects itself. pretty weird.)

[ChrisThomasBone]

In case anyone's wondering, the term that encompasses both microphones and speakers is "transducer", or a device which converts between acoustic information and an electrical signal

[MedlifeCrisis]

So why don't they just plug in solar panels so they light up and power themselves? I can't believe I'm the only person to think of this. Engineers with their fancy degrees pfft

[Syncromatic]

“Diodes are really simple electrical components “... my electronics textbook thoroughly disagrees...

[Tocsin-Bang]

The first observation of the led dates to 1907 when Henry Joseph Round noticed for the first time that when a potential of 10 volts was applied to a carborundum crystal, it emitted yellowish light.

[time-lapserpro]

Solar panels should be used as outdoor lights.
OLED screens should trickle charge your phone.
Thanks for coming to my Ted Talk.

[TommoCarroll]

As always Steve...this was _illuminating_ ! 💡

But for real you’re by far one of the best Science communicators on this platform chap! 🙌