Patent ID: 8379684

Claim:
A light emitting device comprising an active region interposed between n-type and p-type sides of the device and a hole blocking layer interposed between the active region and the n-type side of the device, wherein: the light emitting device is a laser diode; the n-type and p-type sides of the device comprise group III nitride (III-N) semiconductor compounds; the active region comprises an active MQW structure and is configured for electrically-pumped stimulated emission of photons in the green portion of the optical spectrum; the n-type side of the light emitting device comprises an n-doped semiconductor region; the p-type side of the light emitting device comprises a p-doped semiconductor region; the n-doped semiconductor region comprises an n-doped non-polar or n-doped semi-polar substrate; the hole blocking layer (HBL) comprises an n-doped semiconductor material and is interposed between the non-polar or semi-polar substrate and the active region; the n-doped semiconductor region of the laser diode comprises an n-doped waveguide layer interposed between the non-polar or semi-polar substrate and the n-doped hole blocking layer; the n-doped semiconductor region of the laser diode further comprises an n-doped cladding layer interposed between the n-doped waveguide layer and the non-polar or semi-polar substrate; the active region, waveguide layer, and cladding layer are formed as a multi-layered laser diode over the non-polar or semi-polar crystal growth plane of the non-polar or semi-polar substrate such that the waveguide layer guides the stimulated emission of photons from the active region, and the cladding layer promotes propagation of the emitted photons in the waveguide layer; the active MQW structure of the active region comprises a plurality of nanometer scale quantum wells in alternating succession with a plurality of quantum well barrier layers; and the HBL composition is characterized by a wider bandgap than that of the quantum well barrier layers.