Not to sound like a TV commercial or anything, but … how often have you had to throw out white shirts because of unsightly yellow underarm stains? Well, those stains may not be a problem any longer, ...

It’s hard to believe that the first blue LED didn’t arrive until 1993. They look simple, but looks are deceiving (Fig. 1). 1. Image showing a blue InGaN-based LED with gold wire contacts (0.4 × 0.4 mm ...