III-nitride LED with UV emission by auger carrier injection
A III-nitride LED with simultaneous visible and ultraviolet (UV) emission, in which the visible emission is due to conventional InGaN active region mechanisms and the UV emission occurs due to Auger carrier injection into a UV light emitting region, such as impurity-doped AlGaN. The primary application for the III-nitride LED is general airborne pathogen inactivation to prevent the transmission of airborne-mediated pathogens while being safe for humans.
1 . A device, comprising:
a III-nitride-based light emitting structure having both a visible light emitting region and an ultraviolet (UV) light emitting region, wherein:
the visible light emitting region is an InGaN active region emitting violet and/or blue light;
the UV light emitting region is an impurity-doped AlGaN and the impurity-doped AlGaN comprises one or more p-type or n-type AlGaN layers; and
Auger recombination processes lead to generation of high-energy hot carriers in the InGaN active region and the hot carriers transport into the impurity-doped AlGaN layers where the hot carriers recombine to emit UV light.
2 . The device of claim 1 , wherein the InGaN active region has an emission wavelength of 370 nm-460 nm.
3 . The device of claim 1 , wherein the InGaN active region is a single quantum well (SQW).
4 . The device of claim 3 , wherein the SQW has a thickness of less than 5 nm.
5 . The device of claim 1 , wherein a p-side of the III-nitride-based light emitting structure includes a p-type AlGaN cladding region with a wider band gap than the UV light emitting region formed on or above the UV light emitting region.
6 . The device of claim 1 , wherein an n-side of the III-nitride-based light emitting structure includes an n-type AlGaN cladding region with a wider band gap than the UV light emitting region formed below the visible light emitting region.
7 . The device of claim 1 , wherein a p-side of the III-nitride-based light emitting structure includes a p-side contact region formed on or above the UV light emitting region, and the p-side contact region is a highly Mg doped p++-AlGaN region, a p++ GaN region, or a p++-AlN hole-gas.
8 . The device of claim 1 , wherein the UV light emitting region has an emission wavelength below 310 nanometers (UV-B).
9 . The device of claim 1 , wherein the UV light emitting region has an emission wavelength below 280 nanometers (UV-C).
10 . The device of claim 1 , wherein the UV light emitting region has an emission wavelength between 200-230 nanometers (far UV-C).
11 . A method, comprising:
fabricating a III-nitride-based light emitting structure having both a visible light emitting region and an ultraviolet (UV) light emitting region, wherein:
the visible light emitting region is an InGaN active region emitting violet and/or blue light;
the UV light emitting region comprises impurity-doped AlGaN and the impurity-doped AlGaN comprises one or more p-type or n-type AlGaN layers; and
Auger recombination processes lead to generation of high-energy hot carriers in the InGaN active region and the hot carriers transport into the impurity-doped AlGaN where the hot electrons recombine to emit UV light.
12 . A device, comprising:
a III-nitride-based ultraviolet (UV) light emitting structure, wherein:
a large energy bandgap material is grown on or above or below a small energy bandgap material;
the small energy bandgap material is an InGaN-based material;
the large energy bandgap material is an AlGaN-based material;
the large energy bandgap material is an emitting layer or active layer of the structure; and
the small energy bandgap material generates high energy electrons or holes through Auger processes that are injected into the large energy bandgap material where the high energy electrons or holes recombine to emit UV light.
13 . The device of claim 12 , wherein the large energy bandgap material is a p-type layer.
14 . The device of claim 12 , wherein the large energy bandgap material is an n-type layer.
15 . The device of claim 12 , wherein the large energy bandgap material contains at least some scandium.