Re-emitting semiconductor construction with enhanced extraction efficiency
First Claim
1. A device, comprising:
- a stack of semiconductor layers, the stack including;
an active region adapted to convert light at a first wavelength λ
1 to light at a second wavelength λ
2, the active region including at least a first potential well; and
a first inactive region extending from an outer surface of the stack to the active region, a distance from the outer surface to the active region corresponding to a thickness of the first inactive region, the first inactive region characterized in that light at the first wavelength λ
1 propagating therein is not substantially converted to other light;
wherein the stack also includes a plurality of depressions formed therein that extend from the outer surface into the first inactive region, the depressions being characterized by an average depression depth, and wherein the average depression depth is at least 50% of the thickness of the first inactive region, wherein the active region of the semiconductor layer stack also includes a first absorbing layer closely adjacent to, and having a band gap energy greater than a transition energy of the first potential well.
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Accused Products
Abstract
A stack of semiconductor layers forms a re-emitting semiconductor construction (RSC). The stack includes an active region that converts light at a first wavelength to light at a second wavelength, the active region including at least one potential well. The stack also includes an inactive region extending from an outer surface of the stack to the active region. Depressions are formed in the stack that extend from the outer surface into the inactive region. An average depression depth is at least 50% of a thickness of the inactive region or at least 50% of a nearest potential well distance. The depressions may have at least a 40% packing density in plan view. The depressions may also have a substantial portion of their projected surface area associated with obliquely inclined surfaces.
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Citations
14 Claims
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1. A device, comprising:
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a stack of semiconductor layers, the stack including; an active region adapted to convert light at a first wavelength λ
1 to light at a second wavelength λ
2, the active region including at least a first potential well; anda first inactive region extending from an outer surface of the stack to the active region, a distance from the outer surface to the active region corresponding to a thickness of the first inactive region, the first inactive region characterized in that light at the first wavelength λ
1 propagating therein is not substantially converted to other light;wherein the stack also includes a plurality of depressions formed therein that extend from the outer surface into the first inactive region, the depressions being characterized by an average depression depth, and wherein the average depression depth is at least 50% of the thickness of the first inactive region, wherein the active region of the semiconductor layer stack also includes a first absorbing layer closely adjacent to, and having a band gap energy greater than a transition energy of the first potential well.
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2. A multilayer semiconductor construction, comprising:
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a stack of semiconductor layers configured to absorb light at a first wavelength and emit light at a longer second wavelength, the stack including; a potential well; a first semiconductor layer absorbing light at the first wavelength and having an index of refraction n1; and a second semiconductor layer having an index of refraction n2 and comprising a plurality of extraction structures for extracting light from the stack at the second wavelength; wherein n2 is equal to or greater than n1, wherein the potential well and the first semiconductor layer are part of an active region of the stack in which light at the first wavelength is converted to light at the second wavelength, the stack also having an inactive region characterized in that light at the first wavelength propagating therein is not substantially converted to light, the inactive region including the second semiconductor layer and having an inactive region thickness; and wherein the plurality of extraction structures comprise a plurality of depressions characterized by an average depression depth, and wherein the average depression depth is at least 50% of the inactive region thickness.
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3. A device, comprising:
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a stack of semiconductor layers, the stack including; an active region adapted to convert light at a first wavelength λ
1 to light at a second wavelength λ
2, the active region including at least a first potential well; anda first inactive region extending from an outer surface of the stack to the active region, the first inactive region characterized in that light at the first wavelength λ
1 propagating therein is not substantially converted to other light;wherein the first potential well is a nearest potential well to the outer surface of the stack and is characterized by a nearest potential well distance from the outer surface to the first potential well; and wherein the stack also includes a plurality of depressions formed therein that extend from the outer surface into the first inactive region, the depressions being characterized by an average depression depth, and wherein the average depression depth is at least 50% of the nearest potential well distance. - View Dependent Claims (4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14)
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Specification