Abstract: A polarization field assisted DUV-LED including a bottom substrate and a n-contact/injection layer formed on the bottom substrate. The n-contact/injection layer includes: a first region for accommodating strain relaxation; a second region for lateral access with a low sheet resistance and higher conductivity compared to the first region to minimize resistive losses and heat generation; and a third region of a graded vertical injection layer with low vertical resistance to minimize heat loss due to vertical resistance. The DUV-LED also includes a p-contact region, and an emitting active region between the n-contact/injection layer and the p-contact region. The injection of electrons and holes into quantum wells (dots, discs) proceeds due to tunneling of electrons and holes under the barriers due to less than 2 nm thickness of barriers. This carrier injection lowers the Turn ON voltage of LEDs and reduces heat generation compared with conventional thermionic over-barrier injection.

Abstract: A tunnel field-effect transistor device includes a p-type GaN source layer, an ntype GaN drain layer, and an interlayer interfaced between the source-layer and the drain layer. These devices employ polarization engineering in GaN/InN heterojunctions to achieve appreciable interband tunneling current densities. In one example, the interlayer includes an Indium Nitride (InN) layer. In one example, the interlayer includes a graded Indium gallium nitride layer and an InN layer. In one example, the interlayer may include a graded Indium gallium nitride (InxGa1-xN) layer and an Indium gallium nitride (InGaN) layer. In one example, the tunnel field-effect transistor device includes an in-line configuration. In one example, the tunnel field-effect transistor device includes a side-wall configuration. In one example, the tunnel field-effect transistor device includes a nanowire cylindrical gate-all-around geometry to achieve a high degree of gate electrostatic control.

Abstract: A tunnel field-effect transistor device includes a p-type GaN source layer, an n-type GaN drain layer, and an interlayer interfaced between the source-layer and the drain layer. In one example, the interlayer includes an Indium Nitride (InN) layer. In one example, the interlayer includes a graded Indium gallium nitride layer and an InN layer. In one example, the interlayer may include a graded Indium gallium nitride (InxGa1-xN) layer and an Indium gallium nitride (InGaN) layer. In one example, the tunnel field-effect transistor device includes an in-line configuration. In one example, the tunnel field-effect transistor device includes a side-wall configuration.

Abstract: A tunnel field-effect transistor device includes a p-type GaN source layer, an n-type GaN drain layer, and an interlayer interfaced between the source-layer and the drain layer. In one example, the interlayer includes an Indium Nitride (InN) layer. In one example, the interlayer includes a graded Indium gallium nitride layer and an InN layer. In one example, the interlayer may include a graded Indium gallium nitride (InxGa1-xN) layer and an Indium gallium nitride (InGaN) layer. In one example, the tunnel field-effect transistor device includes an in-line configuration. In one example, the tunnel field-effect transistor device includes a side-wall configuration.

Abstract: A tunnel field-effect transistor device includes a p-type GaN source layer, an ntype GaN drain layer, and an interlayer interfaced between the source-layer and the drain layer. These devices employ polarization engineering in GaN/InN heterojunctions to achieve appreciable interband tunneling current densities. In one example, the interlayer includes an Indium Nitride (InN) layer. In one example, the interlayer includes a graded Indium gallium nitride layer and an InN layer. In one example, the interlayer may include a graded Indium gallium nitride (InxGa1-xN) layer and an Indium gallium nitride (InGaN) layer. In one example, the tunnel field-effect transistor device includes an in-line configuration. In one example, the tunnel field-effect transistor device includes a side-wall configuration. In one example, the tunnel field-effect transistor device includes a nanowire cylindrical gate-all-around geometry to achieve a high degree of gate electrostatic control.

Abstract: A two-dimensional (2D) heterojunction interlayer tunneling field effect transistor (Thin-TFET) allows for particle tunneling in a vertical stack comprising monolayers of two-dimensional semiconductors separated by an interlayer. In some examples, the two 2D materials may be misaligned so as to influence the magnitude of the tunneling current, but have a modest impact on gate voltage dependence. The Thin-TFET can achieve very steep subthreshold swing, whose lower limit is ultimately set by the band tails in the energy gaps of the 2D materials produced by energy broadening. These qualities in turn make the Thin-TFET an ideal low voltage, low energy solid state electronic switch.

Abstract: A nitride-based field effect transistor (FET) comprises a compositionally graded and polarization induced doped p-layer underlying at least one gate contact and a compositionally graded and doped n-channel underlying a source contact. The n-channel is converted from the p-layer to the n-channel by ion implantation, a buffer underlies the doped p-layer and the n-channel, and a drain underlies the buffer.

Abstract: A nitride-based field effect transistor (FET) comprises a compositionally graded and polarization induced doped p-layer underlying at least one gate contact and a compositionally graded and doped n-channel underlying a source contact. The n-channel is converted from the p-layer to the n-channel by ion implementation, a buffer underlies the doped p-layer and the re-channel, and a drain underlies the buffer.

Abstract: A compositionally graded semiconductor device and a method of making same are disclosed that provides an efficient p-type doping for wide bandgap semiconductors by exploiting electronic polarization within the crystalline lattice. The compositional graded semiconductor graded device includes a graded heterojunction interface that exhibits a 3D bound polarization-induced sheet charge that spreads in accordance with ??(z)=??·P(z), where ??(z) is a volume charge density in a polar (z) direction, and ? is a divergence operator, wherein the graded heterojunction interface is configured to exhibit substantially equivalent conductivities along both lateral and vertical directions relative to the graded heterojunction interface.

Abstract: A wave amplitude modulator for modulating a transmitted electromagnetic wave includes one or multiple self-gated capacitively coupled pair(s) of electron layers such as semiconductor or semimetal layers. Two electrical contacts are placed to each layer of electrons of the self-gated pair(s), and a power source is electrically connected to them. The power source, by varying the voltage applied between layers of electrons, tunes the electron density thereof, thereby adjusting the optical conductivity thereof, and the change in the optical conductivity of the layers of electrons causes an amplitude modulation of the transmitted electromagnetic wave passing through the capacitively coupled layers of electrons.

Abstract: A wave amplitude modulator for modulating a transmitted electromagnetic wave includes one or multiple self-gated capacitively coupled pair(s) of electron layers such as semiconductor or semimetal layers. Two electrical contacts are placed to each layer of electrons of the self-gated pair(s), and a power source is electrically connected to them. The power source, by varying the voltage applied between layers of electrons, tunes the electron density thereof, thereby adjusting the optical conductivity thereof, and the change in the optical conductivity of the layers of electrons causes an amplitude modulation of the transmitted electromagnetic wave passing through the capacitively coupled layers of electrons.

Abstract: A compositionally graded semiconductor device and a method of making same are disclosed that provides an efficient p-type doping for wide bandgap semiconductors by exploiting electronic polarization within the crystalline lattice. The compositional graded semiconductor graded device includes a graded heterojunction interface that exhibits a 3D bound polarization-induced sheet charge that spreads in accordance with ??(z)=??·P(z), where ??(z) is a volume charge density in a polar (z) direction, and ? is a divergence operator, wherein the graded heterojunction interface is configured to exhibit substantially equivalent conductivities along both lateral and vertical directions relative to the graded heterojunction interface.

Abstract: Novel GaN/AlGaN metal-semiconductor field-effect transistor (MESFET) structures grown without any impurity doping in the channel. A high-mobility polarization-induced bulk channel charge is created by grading the channel region linearly from GaN to Al0.3Ga0.7N over a distance, e.g., 1000 ?. A polarization-doped field effect transistor (PolFET) was fabricated and tested under DC and RF conditions. A current density of 850 mA/mm and transconductance of 93 mS/mm was observed under DC conditions. Small-signal characterization of 0.7 ?m gate length devices had a cutoff frequency, f?=19 GHz, and a maximum oscillation of fmax=46 GHz. The PolFETs perform better than comparable MESFETs with impurity-doped channels, and are suitable for high microwave power applications. An important advantage of these devices over AlGaN/GaN HEMTs is that the transconductance vs. gate voltage profile can be tailored by compositional grading for better large-signal linearity.

Abstract: Novel GaN/AlGaN metal-semiconductor field-effect transistor (MESFET) structures grown without any impurity doping in the channel. A high-mobility polarization-induced bulk channel charge is created by grading the channel region linearly from GaN to Al0.3Ga0.7N over a distance, e.g., 1000 ?. A polarization-doped field effect transistor (PolFET) was fabricated and tested under DC and RF conditions. A current density of 850 mA/mm and transconductance of 93 mS/mm was observed under DC conditions. Small-signal characterization of 0.7 ?m gate length devices had a cutoff frequency, ƒ?=19 GHz, and a maximum oscillation of ƒmax=46 GHz. The PolFETs perform better than comparable MESFETs with impurity-doped channels, and are suitable for high microwave power applications. An important advantage of these devices over AlGaN/GaN HEMTs is that the transconductance vs. gate voltage profile can be tailored by compositional grading for better large-signal linearity.