Techniques are provided for enhancing electrical properties of semiconductor structures. At a semiconductor structure, a heterojunction interface is provided between two dissimilar materials such that a two-dimensional electron gas (2DEG) region is present in the vicinity of the heterojunction. Energy is added to the semiconductor structure such that electrons that are present in the 2DEG region are promoted from below the Fermi level to energy states sufficiently high that the electrons can escape the structure. Electrons are emitted from the semiconductor structure in response to adding the energy such that electrons escape the surface of the semiconductor structure.