The 2014 Nobel Prize in Physics has been won by three Japanese physicists who developed the blue LED (light emitting diode). This is important, as red LEDs were developed in 1962 and green LEDs in the early 1970s, but white light could not be produced by LEDs until a blue LED had been developed. Several large companies tried, but failed, but these three academics succeeded through persistence and ingenuity.
Anyone who has bought a torch (flashlight) in the last few years will know that they almost all now use LEDs. In fact, they use blue LEDs, the kind developed by this Japanese trio, as the blue photons are energetic enough to excite phosphorous which then fluoresces and produces white light.
Computer displays, more and more TVs, and of course smartphones also use LEDs, but in this case they combine red, green and blue LEDs to produce the colour display we see. Smartphones and tablet devices which run on batteries would just not be possible without this technology, as the LEDs used in their screens require significantly less power than any other current technology. Similarly, in lighting applications, be it torches or lighting a room, LEDs use significantly less power than the old incandescent lights and even less than the more recent fluorescent lights to create the same amount of light.
It has been calculated that, by using LEDs, the World-wide use of energy for lighting can be reduced significantly. Currently it is estimated that some 20% of all electricity use is for lighting, but by switching to LED lighting this can be reduced to about 4%.
It is interesting to look at the Nobel Prize in Physics over the last few years to see how it sometimes honours fundamental physics (or astronomy), and other times it honours more applied physics such as this year.
- 2009 – awarded for the development of fibre optic cables, which are used for e.g. transmitting telephone and internet traffic with a much higher efficiency than the old copper-wire technology
- 2010 – the discovery of “wonder material” graphene
- 2011 – the discovery of the acceleration of the expansion of the Universe
- 2012 – work on quantum optics, which promises amongst other things super-fast computers
- 2013 – the discovery of the Higgs boson