Light-emitting diodes having radiative recombination regions with deep sub-micron dimensions are described. The LEDs can be fabricated from indirect bandgap semiconductors and operated under forward bias conditions to produce intense light output from the indirect bandgap material. The light output per unit emission area can be over 500 W cm.sup.−2, exceeding the performance of even high brightness gallium nitride LEDs.

A semiconductor device includes a substrate with at least one epitaxial layer disposed onto the substrate, a 2D silicon carbide layer disposed onto the at least one epitaxial layer. The device also includes a source region. The device also includes a drain region. The device also includes where the 2D silicon carbide layer provides a conducting path between the source region and the drain region. The semiconductor device may include where the 2D silicon carbide layer is a channel layer. The semiconductor device can be a transistor, such as a metal-oxide semiconductor field-effect transistor (MOSFET), or a light-emitting diode.

A semiconductor device includes a substrate with at least one epitaxial layer disposed onto the substrate, a 2D silicon carbide layer disposed onto the at least one epitaxial layer. The device also includes a source region. The device also includes a drain region. The device also includes where the 2D silicon carbide layer provides a conducting path between the source region and the drain region. The semiconductor device may include where the 2D silicon carbide layer is a channel layer. The semiconductor device can be a transistor, such as a metal-oxide semiconductor field-effect transistor (MOSFET), or a light-emitting diode.

An embodiment optical test circuit includes a first optical circuit and a second optical circuit formed on a substrate, an input optical waveguide optically connected to the first optical circuit and the second optical circuit, and an output optical waveguide optically connected to the first optical circuit and the second optical circuit. The optical test circuit also includes a light emitting diode optically connected to the input optical waveguide, and a photodiode optically connected to the output optical waveguide.

An embodiment optical test circuit includes a first optical circuit and a second optical circuit formed on a substrate, an input optical waveguide optically connected to the first optical circuit and the second optical circuit, and an output optical waveguide optically connected to the first optical circuit and the second optical circuit. The optical test circuit also includes a light emitting diode optically connected to the input optical waveguide, and a photodiode optically connected to the output optical waveguide.

A quantum dot including a core and a shell disposed on the core wherein one of the core and the shell includes a first semiconductor nanocrystal including zinc and sulfur and the other of the core and the shell includes a second semiconductor nanocrystal having a different composition from the first semiconductor nanocrystal, the first semiconductor nanocrystal further includes a metal and a halogen configured to act as a Lewis acid in a halide form, an amount of the metal is greater than or equal to about 10 mole percent (mol %) based on a total number of moles of sulfur, and an amount of the halogen is greater than or equal to about 10 mol % based on a total number of moles of sulfur, a method of producing the same, and a composite and an electronic device including the same.

A quantum dot including a core and a shell disposed on the core wherein one of the core and the shell includes a first semiconductor nanocrystal including zinc and sulfur and the other of the core and the shell includes a second semiconductor nanocrystal having a different composition from the first semiconductor nanocrystal, the first semiconductor nanocrystal further includes a metal and a halogen configured to act as a Lewis acid in a halide form, an amount of the metal is greater than or equal to about 10 mole percent (mol %) based on a total number of moles of sulfur, and an amount of the halogen is greater than or equal to about 10 mol % based on a total number of moles of sulfur, a method of producing the same, and a composite and an electronic device including the same.

There is provided an optoelectronic device having an operation range reaching and exceeding 4 μm. The optoelectronic device includes a silicon or a silicon-based substrate and a heterostructure at least partially extending over the substrate. The heterostructure includes a stack of coextending photoactive layers and each photoactive layer includes one or two group IV elements. The photoactive layers are configured for absorbing and/or emitting short-wave infrared and mid-wave infrared radiation. In some embodiments, the short-wave infrared and mid-wave infrared radiation is in a wavelength range extending from about 1 μm to about 8 μm. Methods for manufacturing such an optoelectronic device and device processing are also provided. The methods include forming a heterostructure on a substrate, releasing the heterostructure from the substrate to form a relaxed membrane and transferring the relaxed membrane on a host substrate.

There is provided an optoelectronic device having an operation range reaching and exceeding 4 μm. The optoelectronic device includes a silicon or a silicon-based substrate and a heterostructure at least partially extending over the substrate. The heterostructure includes a stack of coextending photoactive layers and each photoactive layer includes one or two group IV elements. The photoactive layers are configured for absorbing and/or emitting short-wave infrared and mid-wave infrared radiation. In some embodiments, the short-wave infrared and mid-wave infrared radiation is in a wavelength range extending from about 1 μm to about 8 μm. Methods for manufacturing such an optoelectronic device and device processing are also provided. The methods include forming a heterostructure on a substrate, releasing the heterostructure from the substrate to form a relaxed membrane and transferring the relaxed membrane on a host substrate.

In various embodiments, lighting systems include a carrier having a plurality of conductive elements disposed thereon and a light-emitting array. The light-emitting array is disposed over the carrier and includes a plurality of light-emitting diodes (LEDs), each of which has at least two electrical contacts electrically connected to conductive elements.