The principal applications of any sufficiently new and innovative technology always have been—and will continue to be—applications created by that te… - Herbert Kroemer

Whenever I teach my semiconductor device physics course, one of the central messages I try to get across early is the importance of energy band diagrams. I often put this in the form of "Kroemer's Lemma of Proven Ignorance":

If, in discussing a semiconductor problem, you cannot draw an Energy Band Diagram, this shows that you don't know what you are talking about,

Ultimately, progress in applications is not deterministic, but opportunistic, exploiting for new applications whatever new science and technology happen to be coming along.