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 γ 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 J
th
is shown to be lower than conventional heterostructure lasers due to reduced optical losses in the proposed MOS structure.