Abstract: The present invention provides practical methods for n-type doping of graphene, either during graphene synthesis or following the formation of graphene. Some variations provide a method of n-type doping of graphene, comprising introducing a phosphorus-containing dopant fluid to a surface of graphene, under effective conditions to dope the graphene with phosphorus atoms or with phosphorus-containing molecules or fragments. It has been found that substitutional doping with phosphine can effectively modulate the electrical properties of graphene, such as graphene supported on Si or SiC substrates. Graphene sheet resistances well below 200 ohm/sq, and sheet carrier concentrations above 5×1013 cm?2, have been observed experimentally for n-doped graphene produced by the disclosed methods. This invention provides n-doped graphene for various electronic-device applications.

Abstract: A combinationally doped semiconductor layer, a double heterojunction bipolar transistor (DHBT) including a combinationally doped semiconductor layer, and a method of making a combinationally doped semiconductor layer employ a combination of carbon and beryllium doping. The combinationally doped semiconductor layer includes a first sublayer of a semiconductor material doped substantially with beryllium and a second sublayer of the semiconductor material doped substantially with carbon. The DHBT includes a carbon-beryllium combinationally doped semiconductor layer as a base layer. The method of making a combinationally doped semiconductor layer includes growing a first sublayer of the semiconductor layer, the first sublayer being doped substantially with beryllium and growing a second sublayer of the semiconductor layer, the second sublayer being doped substantially with carbon.

Abstract: An electronic device contains a substrate, a sub-collector supported by the substrate, an un-doped layer having a selectively implanted buried sub-collector and supported by the sub-collector, an As-based nucleation layer partially supported by the un-doped layer, a collector layer supported by the As-based nucleation layer, a base layer supported by the collector layer, an emitter layer and a base contact supported by the base layer, an emitter cap layer supported by the emitter layer, an emitter contact supported by the emitter cap layer, and a collector contact supported by the sub-collector. A method provides for selecting a first InP layer, forming an As-based nucleation layer on the first InP layer, and epitaxially growing a second InP layer on the As-based nucleation layer.

Abstract: An electronic device contains a substrate, a sub-collector supported by the substrate, an un-doped layer having a selectively implanted buried sub-collector and supported by the sub-collector, an As-based nucleation layer partially supported by the un-doped layer, a collector layer supported by the As-based nucleation layer, a base layer supported by the collector layer, an emitter layer and a base contact supported by the base layer, an emitter cap layer supported by the emitter layer, an emitter contact supported by the emitter cap layer, and a collector contact supported by the sub-collector. A method provides for selecting a first InP layer, forming an As-based nucleation layer on the first InP layer, and epitaxially growing a second InP layer on the As-based nucleation layer.