Friday, January 27, 2017

What are the biggest discoveries in solid state electronic technology?

Watching an excellent video about the invention of the transistor stimulated to me to think about other big discoveries and inventions in solid state technology.

Who would have thought that huge device would become the basis of an amazing revolution (both technological, economic, and even social...)?

In particular, which are the most ubiquitous ones?
For which devices did both theory and experiment play a role, as they did for the transistor?

I find it worthwhile to think about this for two reasons. First, this semester I am again teaching solid state physics and it is nice to motivate students with examples.
 Second, there is too much hype about basic research in materials and device physics, that glosses over the formidable technical and economic obstacles, to materials and devices becoming ubiquitous. Can history give us some insight as to what is realistic?

Here is a preliminary list of some solid state devices that are ubiquitous.


inorganic semiconductor photovoltaic cell

liquid crystal display

semiconductor laser

optical fiber

giant magnetoresistance used in hard disk drives

blue LED used in solid state lighting

lithium battery

Some of these feature in a nice brochure produced by the USA National Academy of Sciences.

Here are a few that might be on the list but I am not sure about as I think they are more niche applications with limited commercial success. Of course, that may change...

thermoelectric refrigerators

organic LEDs

superconductors (in MRI magnets and as passive filters in mobile phone relay towers )

Is graphene in any commercial device?

What would you add or subtract from the list?


  1. There is another, which you allow (not electrically conducting) per optical fibers: Potassium Titanyl Phosphate nonlinear optical crystals in those green laser pointers. That's high tech.

    Not to mention just plain phosphors, which are solid state, low tech.

    Doug McDonald

  2. I think you may have forgotten the CCD?

  3. Yes. The 2009 Nobel Prize in physics (also for optical fibres). It is interesting that now CCDs seem to be less popular that arrays of semiconductor photodiodes (CMOS sensors)

    Thus, I think I should also add the semiconductor photodiode to the list.

  4. Hi Ross,

    Not what physicists had in mind, but graphene is being used in bike frames - see

    Christoph Meingast