Heterostructures containing one or more sheets of positive charge, or alternately stacked AlGaN barriers and AlGaN wells with specified thickness are provided. Also provided are multiple quantum well structures and p-type contacts. The heterostructures, the multiple quantum well structures and the p-type contacts can be used in light emitting devices and photodetectors.

A monolithic multi-junction solar cell comprising a first III-V subcell and a second III-V subcell and a third III-V subcell and a fourth Ge subcell, wherein the subcells are stacked on top of one another in the specified order, and the first subcell forms the top subcell and a metamorphic buffer is formed between the third subcell and the fourth subcell and all subcells each have an n-doped emitter layer and a p-doped base layer and the emitter doping in the second subcell is lower than the base doping.

A monolithic metamorphic multi-junction solar cell comprising a first III-V subcell and a second III-V subcell and a third III-V subcell and a fourth Ge subcell, wherein the subcells are stacked on top of each other in the indicated order, and the first subcell forms the topmost subcell, and a metamorphic buffer is formed between the third subcell and the fourth subcell and all subcells each have an n-doped emitter layer and a p-doped base layer, and the emitter layer of the second subcell is greater than the base layer.

A monolithic metamorphic multi-junction solar cell comprising a first III-V subcell and a second III-V subcell and a third III-V subcell and a fourth Ge subcell, wherein the subcells are stacked on top of each other in the indicated order, and the first subcell forms the topmost subcell, and a metamorphic buffer is formed between the third subcell and the fourth subcell and all subcells each have an n-doped emitter layer and a p-doped base layer, and the emitter layer of the second subcell is greater than the base layer.

A buffer layer (2), a multiplication layer (3), a light-absorbing layer (5), a window layer (6,7), and a contact layer (8) are sequentially stacked on a semiconductor substrate (1). The window layer (6,7) is doped with an impurity to form a p-type region (9). A bandgap of the window layer (6,7) is greater than a bandgap of the light-absorbing layer (5). The window layer (6,7) includes a first window layer (6), and a second window layer (7) formed on the first window layer (1). A diffusion rate of the impurity in the second window layer (7) is higher than a diffusion rate of the impurity in the first window layer (6). The first window layer (6) is a Ru, Rh or Os-doped InP layer.

A semiconductor device includes an optical source; a photoconductive switch triggered by the optical source; and an enclosure unit that contains the optical source and the photoconductive switch in a single integrated package. The optical source may output a laser. The optical source may be a diode. The enclosure unit may be conductive. The enclosure unit may be non-conductive. The device may include an electrical connector operatively connected to the optical source. The electrical connector may provide power and control signals to the optical source. The electrical connector may be attached to an outer surface of the enclosure unit.

Various embodiments of the present disclosure are directed towards an image sensor having a photodetector disposed in a semiconductor substrate. The photodetector comprises a first doped region comprising a first dopant having a first doping type. A deep well region extends from a back-side surface of the semiconductor substrate to a top surface of the first doped region. A second doped region is disposed within the semiconductor substrate and abuts the first doped region. The second doped region and the deep well region comprise a second dopant having a second doping type opposite the first doping type. An isolation structure is disposed within the semiconductor substrate. The isolation structure extends from the back-side surface of the semiconductor substrate to a point below the back-side surface. A doped liner is disposed between the isolation structure and the second doped region. The doped liner comprises the second dopant.

A high-voltage switch is adapted for use as a medium-voltage direct current circuit breaker, which provides a low-cost, small-footprint device to mitigate system faults. In one example, a method for operating a wideband optical device includes illuminating the wide bandgap optical device with a light within a first range of wavelengths and a first average intensity, allowing a current to propagate therethrough without substantial absorption of the current, illuminating the wide bandgap optical device with light within the first range of wavelengths and a second average intensity that is lower than the first average intensity to allow a sustained current flow though the wide bandgap optical device, and illuminating the wide bandgap optical device with light within a second range of wavelengths to stop or substantially restrict propagation of the current through the wide gap material.

Methods of forming a p-type IV-doped III-VI semiconductor are provided which comprise exposing a substrate to a vapor composition comprising a group III precursor comprising a group III element, a group VI precursor comprising a group VI element, and a group IV precursor comprising a group IV element, under conditions to form a p-type IV-doped III-VI semiconductor via metalorganic chemical vapor deposition (MOCVD) on the substrate. Embodiments make use of a flow ratio defined as a flow rate of the group VI precursor to a flow rate of the group III precursor wherein the flow ratio is below an inversion flow ratio value for the IV-doped III-VI semiconductor.

The present disclosure provides a light detecting device. The light detecting devices includes an insulating layer, a silicon layer, a light detecting layer, N first doped regions and M second doped regions. The silicon layer is disposed over the insulating layer. The light detecting layer is disposed over the silicon layer and extends within at least a portion of the silicon layer. The first doped regions have a first dopant type and are disposed within the light detecting layer. The second doped regions have a second dopant type and are disposed within the light detecting layer. The first doped regions and the second doped regions are alternatingly arranged. M and N are integers equal to or greater than 2.