Abstract: Using a multiple layer, varied composition barrier layer in place of the typical single layer barrier layer of an infrared photodetector results in a device with increased sensitivity and reduced dark current. A first barrier is adjacent the semiconductor contact; a second barrier layer is between the first barrier layer and the absorber layer. The barrier layers may be doped N type or P type with Beryllium, Carbon, Silicon or Tellurium. The energy bandgap is designed to facilitate minority carrier current flow in the contact region and block minority current flow outside the contact region.

Abstract: Consistent with the present disclosure, a current blocking layer is provided between output waveguides carrying light to be sensed by the photodiodes in a balanced photodetector, and the photodiodes themselves. Preferably, the photodiodes are provided above the waveguides and sense light through evanescently coupling with the waveguides. In addition, the current blocking layer may include alternating p and n-type conductivity layers, such that, between adjacent ones of such layers, a reverse biased pn-junction is formed. The pn-junctions, therefore, limit the amount of current flowing from one photodiode of the balanced detector to the other, thereby improving performance.

Abstract: Disclosed is a light emitting device having an isolating insulative layer for isolating light emitting cells from one another and a method of fabricating the same. The light emitting device comprises a substrate and a plurality of light emitting cells formed on the substrate. Each of the light emitting cells includes a lower semiconductor layer, an upper semiconductor layer positioned on one region of the lower semiconductor layer, and an active layer interposed between the lower and upper semiconductor layers. Furthermore, an isolating insulative layer is filled in regions between the plurality of light emitting cells to isolate the light emitting cells from one another. Further, wirings electrically connect the light emitting cells with one another. Each of the wirings connects the lower semiconductor layer of one light emitting cell and the upper semiconductor layer of another light emitting cell adjacent to the one light emitting cell.