> George Cove did not understand how his solar generator worked, and neither did anyone else at the time. It was only with Einstein’s work on the photoelectric

> George Cove did not understand how his solar generator worked, and neither did anyone else at the time. It was only with Einstein’s work on the photoelectric effect (in 1905) and later work in quantum mechanics (1930s and beyond) that the concept of a semiconductor bandgap was realized. Amazing.