A single-heterostructure MOS injection laser

A single-heterostructure metal-oxide-semiconductor (MOS) diode is proposed to obtain laser action in direct-gap semiconductors. Conditions are outlined to achieve a higher minority-carrier injection ratio than is generally obtained in the metal-semiconductor Schottky diodes. Emitted photons are confined in the active layer by a novel combination of heterostructure dielectric discontinuity on one side and the perfectly reflecting surface of the barrier metal on the other. The threshold current density is shown to be lower than conventional heterostructure lasers due to reduced optical losses in the proposed MOS structure.