4 ms·
Rotating molecules enable near 100% efficient OLEDs
- 2bluesc 10y agoWhat does 100% efficiency mean? Does that mean that for some power delivered to the LED load there is a (near) 100% efficient conversion to visible light ("photons")? Would that mean the LEDs operate with practically no heat generation?
- nine_k 10y agoYes, they claim that almost all states excited by electricity now emit visible light; previously 3/4 were in the IR spectrum.
- petra 10y agoThe 3/4 may be true for oled . But for regular LEDs were near 100% already : https://c1cleantechnicacom-wpengine.netdna-ssl.com/files/2014/11/Screen-shot-2014-11-05-at-2.56.38-PM-570x299.png https://c1cleantechnicacom-wpengine.netdna-ssl.com/files/201...
- usrusr 10y agoAnd yet you won't find any shortage of people who will call you a terrible, terrible naysaying pessimist if you dare to voice the prediction that an efficiency jump like from incandescents to CFL or from CFL to LED won't ever happen on top of state of the art LED.
- pareidolia 10y agoThe graph states lumen per watt, not percentage efficiency.
- AndrewDucker 10y agoIndeed. Theoretical maximum is over 200 lm/W: https://en.m.wikipedia.org/wiki/Luminous_efficacy https://en.m.wikipedia.org/wiki/Luminous_efficacy
- usrusr 10y agoOh, that is nicely misleading. The combination of being totally awed by the close proximity to perfection implied by the misreading and being used all of SI fitting together like Legos completely got me (see downvoted comment below, I guess the yaysayers could be right once more - and even now I still think that a photon stream worth one Watt of power, constrained to the visual spectrum could be a very nice alternative unit for the value usually given in lumens).
- xbmcuser 10y agoYup means little or no heat is generated so all the electricity is converted to light.
- Feuilles_Mortes 10y agoUnfortunately this (truly 100%) is impossible ipso facto the 2nd law of thermodynamics.
- Nomentatus 10y agoThis rules out superconductors, does it not?
- 35bge57dtjku 10y agoPlease explain how this is. It seems like something could convert all energy to light without generating heat and while conserving total energy & mass...
- contravariant 10y agoWell, the law they're referring to states that rather than just conserving energy and mass you also can't have a process that lowers entropy. Although it's unclear how this is relevant because, if anything, converting kinetic energy to light increases entropy, or at the very least doesn't decrease it.
- ehsanu1 10y agoYou're probably thinking of heat engines. Extracting 100% efficiency from a heat source is impossible. That doesn't mean that near-100% of non-heat energy can't be converted to another energy type. Eg resistors pretty much convert electricity to heat at a 100% "efficiency" rate..
- Feuilles_Mortes 10y agoHm clearly I've got some more learning to do about this. Thanks!
- legulere 10y agoIn fact because of thermodynamics over 100% efficient LEDs are possible. This was practically demonstrated some years ago: https://phys.org/news/2012-03-efficiency.html https://phys.org/news/2012-03-efficiency.html Converting light to electricity on the other hand cannot reach 100% efficiency.
- std_throwaway 10y agoBut how do they get the light out? Mode density in air is only about half of what it is in organics.