Abstract: A light emitting device includes a semiconductor structure having a light emitting layer disposed between an n-type region and a p-type region. A porous region is disposed between the light emitting layer and a contact electrically connected to one of the n-type region and the p-type region. The porous region scatters light away from the absorbing contact, which may improve light extraction from the device. In some embodiments the porous region is an n-type semiconductor material such as GaN or GaP.

Abstract: A semiconductor light emitting device includes a planar light emitting layer with a wurtzite crystal structure having a <0001> axis roughly parallel to the plane of the layer, referred to as an in-plane light emitting layer. The in-plane light emitting layer may include, for example, a {11 20} or {10 10} InGaN light emitting layer. In some embodiments, the in-plane light emitting layer has a thickness greater than 50 ?.

Abstract: Heterostructure designs are disclosed that may increase the number of charge carriers available in the quantum well layers of the active region of III-nitride light emitting devices such as light emitting diodes. In a first embodiment, a reservoir layer is included with a barrier layer and quantum well layer in the active region of a light emitting device. In some embodiments, the reservoir layer is thicker than the barrier layer and quantum well layer, and has a greater indium composition than the barrier layer and a smaller indium composition than the quantum well layer. In some embodiments, the reservoir layer is graded. In a second embodiment, the active region of a light emitting device is a superlattice of alternating quantum well layers and barrier layers. In some embodiments, the barrier layers are thin such that charge carriers can tunnel between quantum well layers through a barrier layer.

Abstract: Heterostructure designs are disclosed that may increase the number of charge carriers available in the quantum well layers of the active region of III-nitride light emitting devices such as light emitting diodes. In a first embodiment, a reservoir layer is included with a barrier layer and quantum well layer in the active region of a light emitting device. In some embodiments, the reservoir layer is thicker than the barrier layer and quantum well layer, and has a greater indium composition than the barrier layer and a smaller indium composition than the quantum well layer. In some embodiments, the reservoir layer is graded. In a second embodiment, the active region of a light emitting device is a superlattice of alternating quantum well layers and barrier layers. In some embodiments, the barrier layers are thin such that charge carriers can tunnel between quantum well layers through a barrier layer.

Abstract: An infrared LED can function efficiently as both an emitter and a detector at a common wavelength without undesirable characteristics found in avalanche diodes. The LED comprises a graded-bandgap Ga.sub.1-x Al.sub.x As semiconductor material with two semiconductive regions that form a p-n junction. The value of x (the amount of aluminum in the semiconductive material Ga.sub.1-x Al.sub.x As) is varied monotonically as the material is grown so that x decreases monotonically from a value greater than approximately 0.08 at the diode surface on the N side of the p-n junction to a value not less than zero at the diode surface on the P side of the junction. The value of x at the p-n junction is greater than 0 and less than approximately 0.08 as a result of a high initial growth temperature of at least about 930 degrees Celsius.

Abstract: An infrared LED can function efficiently as both an emitter and a detector at a common wavelength without undesirable characteristics found in avalanche diodes. The LED comprises a graded-bandgap Ga.sub.1-x Al.sub.x As semiconductor material with two semiconductive regions that form a p-n junction. The value of x (the amount of aluminum in the semiconductive material Ga.sub.1-x Al.sub.x As) is varied monotonically as the material is grown so that x decreases monotonically from a value greater than 0.08 at the diode surface on the N side of the p-n junction to a value not less than zero at the diode surface on the P side of the junction. The value of x at the p-n junction is greater than 0 and less than 0.08 as a result of a high initial growth temperature of at least about 930 degrees Celsius. A wavelength matched emitter and detector system is realized by adjusting the present diode's initial growth temperature so that its detector response curve substantially overlaps the emission curve of a second diode.

Abstract: The present invention relates to an accumulation mode charge injection device utilizing the extrinsic photoconductivity of a doped semiconductor material to sense infrared radiation. The device is operated at cryostatic temperatures to preclude thermal ionization of the impurity sites and majority carriers are produced by IR photons interacting with these sites. The device utilizes a metal-oxide-semiconductor structure to accumulate the IR photon induced majority carriers at the semiconductor oxide interface under a first bias condition. When the bias is reversed the accumulated charges are injected into an output electrode. The sensor may be used singly or in arrays of similar sensors.

Abstract: An infrared imager having (1) sensing sites comprised of three MIS capacitors, one being an optically sensitive receiver capacitor, a second being an optically insensitive transfer capacitor, and a third being an optically insensitive storage capacitor; and (2) storage control circuit for cycling said sensing sites through a plurality of storage cycles, each cycle comprised of transferring a signal charge from said receiver capacitor to the storage capacitor, prior to readout of the stored signal charge, which is substantially free of background charge, from said optically insensitive storage capacitor using either charge-injection device (CID) or charge-coupled device (CCD) techniques.