An electronic circuit comprises a bipolar transistor that includes a conductive back electrode, an insulator layer over the conductive back electrode and a semiconductor layer of either an n-type or p-type material over the insulator layer. The semiconductor layer includes a doped region, used as the collector and a heavily doped region, bordering the doped region, used as a reachthrough between the insulator layer and the collector contact electrode. A majority-carrier accumulation layer is induced adjacent to the insulator in the doped region of the collector by the application of a bias voltage to the back electrode.