Abstract
We developed a gate-controlled diode that has a Schottky gate on an undoped heterostructure with n- and p-type ohmic regions at opposite ends of the gate. Either two-dimensional electron or hole gas (2DEG or 2DHG) can be formed at the same heterointerface by an electric field from the surface gate. When this diode is biased in the forward direction, current flow is observed in the two gate voltage ranges corresponding to the formation of 2DEG and 2DHG in the undoped heterostructure. When the drain voltage between the p- and n-type contacts exceeds a certain value, a double injection forms a novel current channel that differs from the conventional 2DEG or 2DHG.