This invention pertains to an electronic device containing a semi-insulating substrate, a buffer layer of an antimony-based material disposed on said substrate, a channel layer of InAs.sub.ySb.sub.1-y material disposed on said buffer layer, a barrier layer of an antimony-based disposed on said channel layer, and a cap layer of InAs.sub.ySb.sub.1-y material disposed on said barrier layer, wherein the device can have frequency of on the order of 500 GHz and a reduced power dissipation.