In the fall of 1995, Professor Arthur B Ellis of UWisconsin came to Wabash College - where I was then a senior chemistry major - and gave a presentation about LEDs. At the time I knew of LEDs as the little red or green light bulbs that were pretty much used as power indicators on electronic devices. I didn't - before his talk - have much of an idea how they worked or how important they would come to be in our world now twenty-five years later.
Coincidentally, Dr Ellis had just written Teaching General Chemistry: a materials science companion, a book that my cooperating teacher bought for me after my student teaching semester later that academic year and that I accidentally re-purchased twenty years or so later. (I realize now that I've told this story on the blog before.)
But I digress...I have come to realize that Dr Ellis's lecture at Wabash really laid out the chemistry of LEDs marvelously well because I watched the above video - showing the LEDs and solar panels are of a kind - and the below video - in which Steve Mould explains the science of LEDs and how they turn electricity into light (and the reverse in solar panels) - and realized that I already knew that information...even down to the P- and N-type semiconductor information.
I've never had a chance to thank Dr Ellis for his lecture, so maybe - if I'm lucky - he'll come across one of these blog posts and realize that he's appreciated.
