In the July 2005 issue of Nuts & Volts magazine (which used to be Popular Electronics), an article describes two very simple experiments, explaining the special "field effect transistor (FET)." Without this device, we could not have modern million-transistor integrated circuits, and the article tells why, in easy-to-understand terms. Back issues of the magazine are available via the website
There is more explanation of the FET (and related subjects) in the textbook written by me, if you visit amazon.com, select books, and search for the author, Shanefield. Be sure to look at the 5-star Customer Reviews --- these say the whole book is unusually easy to read (in spite of the somewhat off-putting title!). Note that cheaper versions of the book can be bought from used-book sellers, via amazon, and some public libraries have the book (or will obtain it).
Of course, there are loads of similar books (many quite good!), but not with such clear connections between "how it works" and the important mass-production aspects.
Dan Shanefield
(In case you have some spare time --- here are my 5 very-short, true stories about things going dreadfully wrong, when I was at Bell Labs, before I became a Rutgers professor. AT&T was then the biggest company in the world, and I was able to really screw things up in a big way, which I sometimes did, altho there was always a [somewhat] happy ending. Might be good stories to entertain students: