They are really, really expensive to make compared to silicon, and I want to say they run hotter (but my memory is fuzzy). Silicon has never really been the mo

They are really, really expensive to make compared to silicon, and I want to say they run hotter (but my memory is fuzzy). Silicon has never really been the most ideal material for transistors, but it has always been so cheap in comparison to be the most cost effective. The joke about GaAs is that it will always be the material of tomorrow. (They've been using it in lab settings for decades)