Hmm ... I wrote my Ph.D. thesis on low temperature grown III-V material (GaAs to be precise) and studied InGaAs, and other variations. GaAs would make for awes

Hmm ... I wrote my Ph.D. thesis on low temperature grown III-V material (GaAs to be precise) and studied InGaAs, and other variations. GaAs would make for awesome switching systems, as it is a direct bandgap semiconductor, as opposed to Silicon, which requires phonon mediation. While this is a tremendous technological advantage, you have that minor problem of fabrication. For GaAs, you need ~5 atmospheres of As gas at 550C. Not something anyone wants in their backyard, for good reason. For InP, you need to worry about your supply of rare earth (In) elements, and all the surrounding tech needed to grow ingots of an appropriate orientation material for InP. You have to worry about the role of defects (which is what I simulated), how to dope, how to build structures. Its not simply that it is technologically better, its that there is a whole massive ecosystem around Silicon, that for better or worse, pretty much guarantees that we are going to be running silicon based units for a long ... long time. The joke, and there was one when I was in grad school, about GaAs and other non-Si materials was, they are the materials of the future. And always will be.