Atomically thin LED opens the possibility for invisible displays
news.berkeley.edu
news.berkeley.edu
This is highly simplified, but essentially the LED is now capacitively coupled to its supply on one side, through the insulator*. As a result it has to be driven with AC. Neat trick.
But of course, it would also be neat to just have displays on surfaces where not visible when turned off.
Not sure if that would actually be useful for anything besides a density increase, but it could make color vector displays feasible.
The biggest problem with it at the time was it was running Blackberry OS, which was a reasonable e-mail client, mediocre (and later, noticeably outdated) browser, and abysmal app store and selection of 3rd party apps. I remember saying it would have been a great phone if they had dropped their own OS and went to Android (and spent their software dev time making their version of Android better and building their e-mail client etc on top).
My next phone was an Android something or other, and by then, I was more than happy to give up the physical keyboard to get something more useful than an e-mail interface brick in my pocket.
The problem with physical phone keyboards is that they still tried to be like desktop keyboards. They needed to be more like console controllers.
Apple was not correct about key input, just as they were not correct to remove the TRRS audio jack. They make a lot of decisions that force the market towards where they want it to be, and then people put up with it because they feel they have no viable alternatives. Those who say they like what Apple does might just be loving the one they're with, because they can't have what they love.
You mean glass?
Commercial LEDs consist of a semiconductor material that is electrically injected with positive and negative charges, which produce light when they meet. Typically, two contact points are used in a semiconductor-based light emitting device; one for injecting negatively charged particles and one injecting positively charged particles.
Isn't that a bit too simplified?
That said it sounds like very cool technology although hard to see how electrical wires to each pixel would be as invisible at wall-sized scales.
With a large pitch Cu or Al conductors you can do 5ohm/sq with good transparency. That will let you do 200nits (candela/m2) with the efficiency of these thin LEDs. ITO would be 10x lower conductance and only works in LCDs because they are inverting voltage light valves (not light sources).
If everything worked out you could reasonably view thin LEDs in a dim office environment. That's not really interesting unless it's 3D.
Tiny thin LEDs are necessarily not going to have a huge power output. If the substrate is glass it will have decent thermal conductivity.
I think you can make background dark (from transparent) by using good old LCD technology. Because that's basically what LCD is about.
However in practice I don't think this would be useful - they're considerably less efficient than existing LEDs (currently 1% vs 25-30%) and I think that efficiency is more of a problem than transparency.
> “The materials are so thin and flexible that the device can be made transparent and can conform to curved surfaces,” said Der-Hsien Lien, a postdoctoral fellow at UC Berkeley and a co-first author
https://www.youtube.com/watch?v=IJQzPrkkH6A https://www.youtube.com/watch?v=Lv46YU-X9Xs
I'm confuzzled by the 'news', although the AC drive, vice DC is interesting I suppose.