Patent attributes
Embodiments disclose LEDs that operate using impact ionization. Devices include a first conductivity type layer, an intrinsic layer, and an impact ionization layer. In some embodiments, a charge layer is on the intrinsic layer, where the charge layer comprises a first material and has a net charge. The impact ionization layer comprises a second material. The charge layer forms a barrier for transporting carriers until a bias of at least 1.5 times a bandgap of the second material is applied, and a resulting electric field in the impact ionization layer is greater than or equal to a threshold for the second material. In some embodiments the first intrinsic layer is on the first conductivity type layer and is made of the first material, and a compositional step at an interface between the intrinsic layer and the impact ionization layer creates a barrier for transporting carriers.