A device, such as an electroabsorption modulator, can modulate a light intensity by controllably absorbing a selectable fraction of the light. The device can include a substrate. A waveguide positioned on the substrate can guide light. An active region positioned on the waveguide can receive guided light from the waveguide, absorb a fraction of the received light, and return a complementary fraction of the received light to the waveguide. Such absorption produces heat, mostly at an input portion of the active region. The input portion of the active region can be thermally coupled to the substrate, which can dissipate heat from the input portion, and can help avoid thermal runaway of the device. The active region can be thermally isolated from the substrate away from the input portion, which can maintain a relatively low thermal mass for the active region, and can increase efficiency when heating the active region.

An exemplary quantum dot device can be provided, which can include, for example, at least three conductive layers and at least two insulating layers electrically insulating the at least three conductive layers from one another. For example, one of the conductive layers can be composed of a different material than the other two of the conductive layers. The conductive layers can be composed of (i) aluminum, (ii) gold, (iii) copper or (iv) polysilicon, and/or the at least three conductive layers can be composed at least partially of (i) aluminum, (ii) gold, (iii) copper or (iv) polysilicon. The insulating layers can be composed of (i) silicon oxide, (ii) silicon nitride and/or (iii) aluminum oxide.

A photoconductive device that includes a semiconductor substrate, an antenna assembly, and a photoconductive assembly with one or more plasmonic contact electrodes. The photoconductive assembly can be provided with plasmonic contact electrodes that are arranged on the semiconductor substrate in a manner that improves the quantum efficiency of the photoconductive device by plasmonically enhancing the pump absorption into the photo-absorbing regions of semiconductor substrate. In one exemplary embodiment, the photoconductive device is arranged as a photoconductive source and is pumped at telecom pump wavelengths (e.g., 1.0-1.6 μm) and produces milliwatt-range power levels in the terahertz (THz) frequency range.

A quantum well device includes a first layer of a first two-dimensional material, a second layer of a second two-dimensional material, and a third layer of a third two-dimensional material disposed between the first layer and second layer. The first layer, the second layer, and the third layer are adhered predominantly by van der Waals force.

Certain embodiments of the present invention may be directed to a transistor structure. The transistor structure may include a semiconductor substrate. The semiconductor substrate may include a drift region, a collector region, an emitter region, and a lightly-doped/undoped region. The lightly-doped/undoped region may be lightly-doped and/or undoped. The transistor structure may also include a heterostructure. The heterostructure forms a heterojunction with the lightly-doped/undoped region. The transistor structure may also include a collector terminal. The collector terminal is in contact with the collector region. The transistor structure may also include a gate terminal. The gate terminal is in contact with the heterostructure. The transistor structure may also include an emitter terminal. The emitter terminal is in contact with the lightly-doped/undoped region and the emitter region.

Methods of making a semiconductor layer from nanocrystals are disclosed. A film of nanocrystals capped with a ligand can be deposited onto a substrate; and the nanocrystals can be irradiated with one or more pulses of light. The pulsed light can be used to substantially remove the ligands from the nanocrystals and leave the nanocrystals unsintered or sintered, thereby providing a semiconductor layer. Layered structures comprising these semiconductor layers with an electrode are also disclosed. Devices comprising such layered structures are also disclosed.

A plasmonic field-enhanced photodetector is disclosed. The photodetector may generate photocurrent by absorbing surface plasmon polaritons (SPPs) generated by combining surface plasmons (SPs) with photons of a light wave.

Designs of extremely high efficiency solar cells are described. A novel alternating bias scheme enhances the photovoltaic power extraction capability above the cell band-gap by enabling the extraction of hot carriers. When applied in conventional solar cells, this alternating bias scheme has the potential of more than doubling their yielded net efficiency. When applied in conjunction with solar cells incorporating quantum wells (QWs) or quantum dots (QDs) based solar cells, the described alternating bias scheme has the potential of extending such solar cell power extraction coverage, possibly across the entire solar spectrum, thus enabling unprecedented solar power extraction efficiency. Within such cells, a novel alternating bias scheme extends the cell energy conversion capability above the cell material band-gap while the quantum confinement structures are used to extend the cell energy conversion capability below the cell band-gap. Light confinement cavities are incorporated into the cell structure in order to allow the absorption of the cell internal photo emission, thus further enhancing the cell efficiency.

Semiconductor device assemblies having solid-state transducer (SST) devices and associated semiconductor devices, systems, and are disclosed herein. In one embodiment, a method of forming a semiconductor device assembly includes forming a support substrate, a transfer structure, and a plurality semiconductor structures between the support substrate and the transfer structure. The method further includes removing the support substrate to expose an active surface of the individual semiconductor structures and a trench between the individual semiconductor structures. The semiconductor structures can be attached to a carrier substrate that is optically transmissive such that the active surface can emit and/or receive the light through the carrier substrate. The individual semiconductor structures can then be processed on the carrier substrate with the support substrate removed. In some embodiments, the individual semiconductor structures are simulated from the semiconductor device assembly and include a section of the carrier substrate attached to each of the individual semiconductor structures.

A semiconductor device having a highly doped quantum structure emitter is disclosed. In an embodiment, the semiconductor device includes a quantum structure emitter. The quantum structure emitter includes of a first layer made of an undoped semiconductor material with a large band gap, a second, middle, highly doped layer made of a semiconductor material with a low band gap and a third, undoped layer made of a semiconductor material with a large band gap.