Energy-filtered cold electron devices use electron energy filtering through discrete energy levels of quantum wells or quantum dots that are formed through band bending of tunneling barrier conduction band. These devices can obtain low effective electron temperatures of less than or equal to 45K at room temperature, steep electrical current turn-on/turn-off capabilities with a steepness of less than or equal to 10 mV/decade at room temperature, subthreshold swings of less than or equal to 10 mV/decade at room temperature, and/or supply voltages of less than or equal to 0.1 V.

In accordance with an embodiment, a diode comprises a substrate, a dielectric material including an opening that exposes a portion of the substrate, the opening having an aspect ratio of at least 1, a bottom diode material including a lower region disposed at least partly in the opening and an upper region extending above the opening, the bottom diode material comprising a semiconductor material that is lattice mismatched to the substrate, a top diode material proximate the upper region of the bottom diode material, and an active diode region between the top and bottom diode materials, the active diode region including a surface extending away from the top surface of the substrate.

A semiconductor device includes a first diode connected transistor of a first conductivity type and a second diode connected transistor of a second conductivity type connected in series, each of the first and second diode connected transistors being configured to exhibit negative differential resistance in response to an applied voltage. The first drain and first source regions of the first diode connected transistor include dopants of the first conductivity type at degenerate dopant concentration levels and a gate of the first diode connected transistor has a work function that corresponds to that of the semiconductor containing dopants of the second conductivity type. The second drain and second source regions of the second diode connected transistor include dopants of the second conductivity type at degenerate dopant concentration levels and a gate of the second diode connected transistor has a work function that corresponds to that of the semiconductor containing dopants of the first conductivity type.

To provide a resonant tunneling diode and a terahertz oscillator capable of further performance improvement. The resonant tunneling diode includes: a multi-quantum well structure that is composed of a group-III nitride semiconductor; a first electrode that is connected to one of sides of the multi-quantum well structure; and a second electrode that is connected to the other side of the multi-quantum well structure. The multi-quantum well structure includes a first barrier layer, a first quantum well layer, a second barrier layer, a second quantum well layer, and a third barrier layer, which are arranged in order from the first electrode toward the second electrode. The first barrier layer, the second barrier layer, and the third barrier layer have a thickness through which a carrier can pass by a tunneling effect. The first quantum well layer and the second quantum well layer each have a potential gradient by spontaneous polarization or a sum of spontaneous polarization and piezoelectric polarization, and have mutually different thicknesses. The first quantum well layer and the second quantum well layer have compositions with different magnitudes of potential energy.

A terahertz element of an aspect of the present disclosure includes a semiconductor substrate, first and second conductive layers, and an active element. The first and second conductive layers are on the substrate and mutually insulated. The active element is on the substrate and electrically connected to the first and second conductive layers. The first conductive layer includes a first antenna part extending along a first direction, a first capacitor part offset from the active element in a second direction as viewed in a thickness direction of the substrate, and a first conductive part connected to the first capacitor part. The second direction is perpendicular to the thickness direction and first direction. The second conductive layer includes a second capacitor part, stacked over and insulated from the first capacitor part. The substrate includes a part exposed from the first and second capacitor parts. The first conductive part has a portion spaced apart from the first antenna part in the second direction with the exposed part therebetween as viewed in the thickness direction.

One or more systems, devices and/or methods provided herein relate to a device that can facilitate generation of a pulse to affect a qubit and to a method that can facilitate fabrication of a semiconductor device. The semiconductor device can comprise an RTD and an FET co-integrated in a common layer extending along a substrate. A method for fabricating the semiconductor device can comprise applying, at a substrate layer, a template structure comprising an opening, a cavity and a seed structure comprising a seed material and a seed surface, and sequentially growing along the substrate a plurality of diode layers of an RTD and a plurality of transistor layers of an FET within the cavity of the template structure from the seed surface, wherein the RTD and FET are co-integrated along the substrate.

The present disclosure provides a resonant tunneling diode including: a first barrier layer; a second barrier layer; a potential well layer between the first barrier layer and the second barrier layer, materials of the first barrier layer, the second barrier layer, and the potential well layer including a group III nitride, a material of the potential well layer including a gallium element; a first barrier layer between the first barrier layer and the potential well layer; and/or a second barrier layer between the second barrier layer and the potential well layer.