Abstract: In one aspect, optoelectronic devices are described herein. In some implementations, an optoelectronic device comprises a photovoltaic cell. The photovoltaic cell comprises a space-charge region, a quasi-neutral region, and a low bandgap absorber region (LBAR) layer or an improved transport (IT) layer at least partially positioned in the quasi-neutral region of the cell.

Abstract: In one aspect, optoelectronic devices are described herein. In some implementations, an optoelectronic device comprises a photovoltaic cell. The photovoltaic cell comprises a space-charge region, a quasi-neutral region, and a low bandgap absorber region (LBAR) layer or an improved transport (IT) layer at least partially positioned in the quasi-neutral region of the cell.

Abstract: Photovoltaic (PV) cell structures are disclosed. In one example embodiment, a PV cell includes an emitter layer, a base layer adjacent to the emitter layer, and a back surface field (BSF) layer adjacent to the base layer. The BSF layer includes a first layer, and a second layer adjacent to the first layer. The first layer includes a first material and the second layer includes a second material different than the first material.

Abstract: A type-II tunnel junction is disclosed that includes a p-doped AlGaInAs tunnel layer and a n-doped InP tunnel layer. Solar cells are further disclosed that incorporate the high bandgap type-II tunnel junction between photovoltaic subcells.

Abstract: A solar cell structure including a solar cell having a front surface and a back surface, a reflective layer disposed proximate the back surface and a flexible support layer disposed between the back surface and the reflective layer.

Abstract: A semiconductor structure including a bonding layer connecting a first semiconductor wafer layer to a second semiconductor wafer layer, the bonding layer including an electrically conductive carbonaceous component and a binder component.

Abstract: A solar cell including a base region, a back surface field layer and a delta doping layer positioned between the base region and the back surface field layer.

Abstract: In one aspect, semiconductor structures are described herein. A semiconductor structure, in some implementations, comprises a first semiconductor layer having a first bandgap and a first lattice constant and a second semiconductor layer having a second bandgap and a second lattice constant. The second lattice constant is lower than the first lattice constant. Additionally, a transparent metamorphic buffer layer is disposed between the first semiconductor layer and the second semiconductor layer. The buffer layer has a constant or substantially constant bandgap and a varying lattice constant. The varying lattice constant is matched to the first lattice constant adjacent the first semiconductor layer and matched to the second lattice constant adjacent the second semiconductor layer. The buffer layer comprises a first portion comprising AlyGazIn(1-y-z)As and a second portion comprising GaxIn(1-x)P.

Abstract: In one aspect, optoelectronic devices are described herein. In some implementations, an optoelectronic device comprises a photovoltaic cell. The photovoltaic cell comprises a space-charge region, a quasi-neutral region, and a low bandgap absorber region (LBAR) layer or an improved transport (IT) layer at least partially positioned in the quasi-neutral region of the cell.

Abstract: In one aspect, optoelectronic devices are described herein. In some implementations, an optoelectronic device comprises a photovoltaic cell. The photovoltaic cell comprises a space-charge region, a quasi-neutral region, and a low bandgap absorber region (LBAR) layer or an improved transport (IT) layer at least partially positioned in the quasi-neutral region of the cell.

Abstract: Photovoltaic (PV) cell structures are disclosed. In one example embodiment, a PV cell includes an emitter layer, a base layer adjacent to the emitter layer, and a back surface field (BSF) layer adjacent to the base layer. The BSF layer includes a first layer, and a second layer adjacent to the first layer. The first layer includes a first material and the second layer includes a second material different than the first material.

Abstract: Photovoltaic (PV) cell structures are disclosed. In one example embodiment, a PV cell includes an emitter layer, a base layer adjacent to the emitter layer, and a back surface field (BSF) layer adjacent to the base layer. The BSF layer includes a first layer, and a second layer adjacent to the first layer. The first layer includes a first material and the second layer includes a second material different than the first material.

Abstract: In one aspect, semiconductor structures are described herein. A semiconductor structure, in some implementations, comprises a first semiconductor layer having a first bandgap and a first lattice constant and a second semiconductor layer having a second bandgap and a second lattice constant. The second lattice constant is lower than the first lattice constant. Additionally, a transparent metamorphic buffer layer is disposed between the first semiconductor layer and the second semiconductor layer. The buffer layer has a constant or substantially constant bandgap and a varying lattice constant. The varying lattice constant is matched to the first lattice constant adjacent the first semiconductor layer and matched to the second lattice constant adjacent the second semiconductor layer. The buffer layer comprises a first portion comprising AlyGazIn(1-y-z)As and a second portion comprising GaxIn(1-x)P.

Abstract: In one aspect, optoelectronic devices are described herein. In some implementations, an optoelectronic device comprises a photovoltaic cell. The photovoltaic cell comprises a space-charge region, a quasi-neutral region, and a low bandgap absorber region (LBAR) layer or an improved transport (IT) layer at least partially positioned in the quasi-neutral region of the cell.

Abstract: The disclosure provides for a direct wafer bonding method including providing a bonding layer upon a first and second wafer, and directly bonding the first and second wafers together under heat and pressure. The method may be used for directly bonding an GaAs-based, InP-based, GaP-based, GaSb-based, or Ga(In)N-based device to a GaAs device by introducing a highly doped (Al)(Ga)InP(As)(Sb) layer between the devices. The bonding layer material forms a bond having high bond strength, low electrical resistance, and high optical transmittance.

Abstract: In one aspect, semiconductor structures are described herein. A semiconductor structure, in some implementations, comprises a first semiconductor layer having a first bandgap and a first lattice constant and a second semiconductor layer having a second bandgap and a second lattice constant. The second lattice constant is lower than the first lattice constant. Additionally, a transparent metamorphic buffer layer is disposed between the first semiconductor layer and the second semiconductor layer. The buffer layer has a constant or substantially constant bandgap and a varying lattice constant. The varying lattice constant is matched to the first lattice constant adjacent the first semiconductor layer and matched to the second lattice constant adjacent the second semiconductor layer. The buffer layer comprises a first portion comprising AlyGazIn(1-y-z)As and a second portion comprising GaxIn(1-x)P.

Abstract: In one aspect, optoelectronic devices are described herein. In some implementations, an optoelectronic device comprises a photovoltaic cell. The photovoltaic cell comprises a space-charge region, a quasi-neutral region, and a low bandgap absorber region (LBAR) layer or an improved transport (IT) layer at least partially positioned in the quasi-neutral region of the cell.

Abstract: Technologies for a process used to reduce the height of a raised profile of a device. One or more raised profiles on one or more layers of a device are removed using a combined chemical-mechanical polishing/etching process. In some implementations, a protective layer is applied to a top layer of a device grown on a substrate. A combined chemical-mechanical polishing/etching process may commence whereby one or more raised profiles of the protective layer are removed through a planarization process, exposing at least a portion of a raised profile of a layer below the protective layer. Material may be removed using an etchant to reduce the height of the raised profile.

Abstract: Technologies for a process used to reduce the height of a raised profile of a device. One or more raised profiles on one or more layers of a device are removed using a combined chemical-mechanical polishing/etching process. In some implementations, a protective layer is applied to a top layer of a device grown on a substrate. A combined chemical-mechanical polishing/etching process may commence whereby one or more raised profiles of the protective layer are removed through a planarization process, exposing at least a portion of a raised profile of a layer below the protective layer. Material may be removed using an etchant to reduce the height of the raised profile.

Abstract: A semiconductor device may include a first subassembly and a second subassembly. The first subassembly may include a first bonding layer. The second subassembly may include a second substrate and a second bonding layer directly bonded to the first bonding layer. The first bonding layer and the second bonding layer may be lattice-mismatched to one another. At least one of the following may be selected: the first bonding layer is lattice-mismatched to the first substrate, and the second bonding layer is lattice-mismatched to the second substrate.