KR20240042113A - Semiconductor light-emitting device with near-field surface-grating-resonant reflector - Google Patents

Abstract

The light emitting device includes a semiconductor diode structure, a surface-lattice-mode (SLR) structure facing the backside of the diode structure, and a reflector facing the backside of the SLR structure. The diode structure includes first and second doped semiconductor layers and an active layer therebetween; The active layer emits output light of the nominal emission vacuum wavelength (λ ₀ ) propagating within the diode structure. The SLR structure includes an index-matching layer, a low-index layer, and scattering elements, and is within near-field proximity to the active layer for λ ₀ . At least a portion of the output light that propagates perpendicularly within the diode structure with respect to the device emission surface exits the diode structure as device output light. The scattering elements include laterally propagating surface-grating-resonance modes supported by the SLR structure to redirect output light propagating within the device to propagate perpendicularly toward the device exit surface.

Description

Semiconductor light-emitting device with near-field surface-grating-resonant reflector

claim priority

This application is related to (i) U.S. Provisional Application No. 63/233,043, entitled “Semiconductor light-emitting device with near-field surface-lattice-resonance reflector,” filed August 13, 2021, in the name of Abdelkhalik et al.; (ii) Claiming priority to U.S. Provisional Application No. 17/880,976, entitled “Semiconductor light-emitting device with near-field surface-lattice-resonance reflector,” filed August 4, 2022, by Abdelkhalik et al. , both of the above applications are incorporated herein by reference as if set forth in their entirety.

The field of the present invention relates to semiconductor light emitting devices. In particular, a semiconductor light emitting device comprising a near-field surface-grating-resonant reflector is disclosed.

The semiconductor light emitting device of the present invention includes a semiconductor diode structure, a surface-lattice-resonance (SLR) structure, and a reflector. The semiconductor diode structure includes first and second doped semiconductor layers and an active layer between a back surface of the first semiconductor layer and a front surface of the second semiconductor layer. The active layer emits output light propagating within the diode structure at the nominal emission vacuum wavelength (λ ₀ ) due to current flow through the device. The SLR structure is positioned against the rear surface of the second semiconductor layer, and the reflector is positioned against the rear surface of the SLR structure. The second semiconductor layer is sufficiently thin such that the SLR structure is within near-field proximity to the active layer for the vacuum wavelength (λ ₀ ). At least a portion of the front surface of the first semiconductor layer is arranged as a device exit surface, through which an output propagates perpendicularly within the diode structure with respect to the device exit surface and is incident on the device exit surface within the diode structure. At least a portion of the light exits the diode structure as device output light. The device exit surface may include an anti-reflection layer or coating.

The SLR structure includes (i) an index-matched layer of substantially transparent dielectric material positioned against the back surface of the second semiconductor layer and having an effective refractive index substantially equal to the effective refractive index of the second semiconductor layer, (ii) a lower-index layer of substantially transparent dielectric material positioned against the rear surface of the index-matching layer and having an effective refractive index lower than the effective refractive index of the index-matching layer, and (iii) an index- It includes a plurality of scattering elements positioned on or within the index-matching layer. The scattering elements are arranged such that the SLR structure supports one or more SLR modes; Coupling of output light to one or more of the SLR modes results in redirecting a non-zero fraction of output light propagating within the device, including laterally propagating output light, to propagate vertically toward the device exit surface. The near-field proximity of the SLR structure to the active layer, and the structural arrangement of the SLR structure, result in the device having (i) a relatively improved Purcell factor, and (ii) a relatively increased output light propagating within the device escape cone. fraction, (iii) a relatively reduced average total number of internal redirections and internal reflections per photon of output light prior to exiting the device, or (iv) a relatively improved photon extraction efficiency. .

Objects and advantages regarding light emitting devices may become apparent upon reference to the exemplary embodiments illustrated in the drawings and disclosed in the written description or appended claims that follow.

This overview is provided to introduce in a simplified form a selection of concepts that are further described below in the detailed description. This Summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter.

1A and 1B are schematic cross-sectional views of two general examples of light-emitting devices of the present invention.
Figure 2A is a schematic cross-sectional view of a specific example of a light-emitting device of the present invention; FIG. 2B is a plot of radiant intensity versus emission angle (not sine-corrected) for the device of FIG. 2A.
3 and 4 are schematic cross-sectional views of two conventional light-emitting devices. Figures 5A and 5B are plots of radiant intensity (sine-corrected in Figure 5B) as a function of emission angle for the devices of Figures 3 and 4.
The depicted embodiments are shown schematically only; Not all features may be shown in all detail or to scale; For clarity, certain features or structures may be exaggerated or understated relative to others, or omitted entirely; Drawings should not be considered to be to scale unless explicitly indicated as being to scale. For example, light-emitting devices depicted as having a small number of scattering elements typically have hundreds or thousands of such elements per millimeter; The number of scattering elements is reduced in the figures for clarity. Additionally, the height, depth, or width of each layer or scattering element can often be exaggerated relative to those of other structures, such as the thickness of the underlying substrate or semiconductor layer. The illustrated embodiments are examples only and should not be construed as limiting the scope of the disclosure or the appended claims.

The following detailed description should be interpreted with reference to the drawings, in which like reference numerals refer to similar elements throughout the different drawings. The drawings are not necessarily to scale, depict selective examples, and are not intended to limit the scope of the invention. The detailed description illustrates the principles of the invention by way of example and not by way of limitation.

Typical light emitting diodes (LEDs) include one or more light-emitting active layers within a semiconductor diode structure that emit light when driven by electric current. The back surface (and in some examples one or more or all of the side surfaces) of the semiconductor diode structure typically directs light incident within the semiconductor diode structure to the front surface of the diode structure (also referred to herein as the exit surface or exit surface). It includes a reflector that reflects the propagation towards. Many semiconductor materials have relatively large refractive indices (often about 3 or higher), which will result in a large fraction of the emitted light being trapped within the semiconductor diode structure by total internal reflection. In some conventional light emitting diodes, texturing (e.g., corrugations, bumps or dimples, or other surface features or roughness) is formed on or attached to the front emitting surface of the semiconductor diode structure. do. The back-surface reflector in such so-called cavity emitters ensures that almost all light propagating within the semiconductor diode structure ends up incident on the front surface. Front-surface texturing at least partially spoils total internal reflection, allowing a portion of the emitted light to escape the semiconductor diode structure through the front surface as device output light, while other portions escape from the flat exit surface. It functions to redirect the propagation into the semiconductor diode structure in directions different from the direction of the specular reflection. Such redirected portions eventually reach the anterior surface again and have another opportunity to escape by penetration through the anterior surface. This light recycling process continues, with each so-called "photon bounce" within the effective "LED cavity" formed by the back-surface reflector and front-surface texturing (i.e. between the front and back surfaces respectively through the semiconductor diode structure). back and forth) increases the overall probability that a photon will escape through the front surface as device output light.

An example of a conventional LED cavity emitter 10 is schematically illustrated in FIG. 3 and includes a semiconductor diode structure 12, a light-emitting active layer 14 within the semiconductor diode structure 12, and a semiconductor diode structure 12 on the front surface of the semiconductor diode structure 12. Texturing (16), and a metal reflector (18) on the rear surface of the semiconductor diode structure (12). Another example of a conventional LED cavity emitter 20 is schematically illustrated in FIG. 4 and includes a semiconductor diode structure 12, a light-emitting active layer 14 within the semiconductor diode structure 12, and texturing on the front surface of the diode structure 12. (16), a dielectric layer (19) on the rear surface of the diode structure (12), and a metal reflector (18) on the rear surface of the dielectric layer (19). In both Figures 3 and 4, reflector 18 shows only specular reflection. Figures 5A and 5B are plots of the radiation intensity as a function of the emission angle for the direction perpendicular to the active layer 14 (sine-corrected in Figure 5B to take into account integration over the full range of azimuths).

In many examples, the probability per bounce of a photon being transmitted through the front surface is relatively low, which in turn requires a relatively large number of round trips (e.g., depending on the specific materials used) to achieve a sufficiently high photon extraction probability. 10 to 50 bounces) are required to achieve extraction efficiencies approaching 90%. Such a relatively large number of round trips, or photon bounces, in turn results in a sufficiently low optical loss per round through the semiconductor diode structure (e.g., loss due to absorption by the diode structure, active layer, or reflector materials, or insufficient reflectivity of the reflector). ) is requested. Such low-loss requirements can, in some cases, skyrocket the cost or complexity of the light emitting device (e.g., use of silver reflectors instead of aluminum; use of multi-layer thin film reflectors instead of metal reflectors; or diode structures, active layers, or the use of higher purity materials for the reflector), or may result in devices with low extraction efficiency (e.g., when low-loss alternatives are unavailable or prohibitively expensive). Additionally, only a relatively small fraction (e.g., less than 13%) of the light emitted by active layer 14 is incident at an angle within the escape cone upon first encounter with the exit surface, and thus typically has the opportunity to be transmitted rather than reflected inward. am.

Devices arranged according to FIG. 3 have increased (relative to the so-called semi-infinite half-cavity model, in which there are no structures close enough to the active layer 14 to affect their emission properties). This can be “tuned” by choosing a suitable distance between the active layer 14 and the metal layer 18 resulting in a higher total radiated emission and a higher fraction of the emitted light propagating within the escape cone. Devices arranged according to Figure 3 also tend to have lower extraction efficiency due to unwanted absorption by the metal layer 18. By arranging the devices according to FIG. 4 to include a dielectric layer 19, such absorption can be reduced and the extraction efficiency is increased. However, devices arranged according to Figure 4 tend to exhibit a reduction in total radiated emission and a smaller fraction of the emitted light propagating within the escape cone.

For the purposes of this disclosure and the appended claims, “angle of incidence” and “angle of incidence” of light incident on a surface or interface refer to the angle between the direction of propagation of the incident light and a vector perpendicular to the surface or interface. Accordingly, light propagating at orthogonal incidence with respect to the surface will have an angle of incidence of 0°, while light propagating with near grazing incidence with respect to the surface will have an angle of incidence approaching 90°. For the purposes of this disclosure and the appended claims, the “critical angle” (designated θ _C ) for light incident on a surface or interface between media of different refractive indices is defined as the light propagating within the higher refractive index medium. refers to the angle of incidence at which light beyond that angle undergoes total internal reflection within a higher refractive index medium. Therefore, the critical angle θ _C defines the escape cone for a given surface or interface, such that light incident outside the escape cone is totally internally reflected, and light incident within the escape cone may be transmitted by refraction. .

For the purposes of this disclosure and the appended claims, “oblique light,” “oblique radiation,” “obliquely propagating,” “lateral light,” “lateral radiation,” “lateral propagation,” and the like refer to substrate, layer, and the like. , or will refer to light that propagates within a diode structure at angles of incidence greater than θ _C with respect to its front and back surfaces (i.e., outside the escape cone), “perpendicular light”, “perpendicular radiation”. , “vertically propagating”, “vertical light”, “vertical radiation”, “vertically propagating”, etc., refers to θ within a substrate or diode structure, with respect to surfaces, even if they are not literally perpendicular or perpendicular to such surfaces. We will refer to light that propagates at angles of incidence less than _C (i.e., inside the escape cone), and “normal” will be reserved to describe light that is incident at an angle of incidence substantially equal to 0°.

For the purposes of this disclosure and the appended claims, any arrangement in which a layer, surface, substrate, diode structure, or other structure is “on,” “on,” or “abutting” another such structure. , will include arrangements with direct contact between two structures, as well as arrangements containing some intervening structure between them. Conversely, any arrangement in which a layer, surface, substrate, diode structure, or other structure is “directly on,” “directly on,” or “directly abutting” another such structure creates a gap between the two structures. Only arrangements with direct contact will be included. For the purposes of this disclosure and the appended claims, a layer, structure, or material described as “transparent” and “substantially transparent” means that, at the nominal emission vacuum wavelength (λ ₀ ), the light emitting device has operationally acceptable parameters. a sufficiently high level of optical transmission or sufficiently low optical loss to function within a range (e.g., output power or brightness, conversion or extraction efficiency, or other figure-of-merit, including those described below). It will indicate the level (due to absorption, scattering, or other loss mechanisms).

(e.g., for one or both of the arrangements of Figure 3 or Figure 4) (i) improved photon extraction efficiency (e.g., greater than 80%), (ii) reduced number of photon bounces (e.g., less than or equal to 30), (iii) an improved total radiant emission, (iv) an improved Purcell factor, or (v) an improved fraction of emitted light that propagates within the escape cone before first encountering the escape surface. It would be desirable. Accordingly, the semiconductor light emitting device 300 of the present invention that can achieve one or more of such improvements includes a semiconductor diode structure 310, a surface-lattice-resonance (SLR) structure 320, and a reflector 305. Includes. Two general examples of devices 300 of the invention are schematically illustrated in Figures 1A and 1B, and one specific example of a device 300 of the invention is schematically illustrated in Figures 2A-2C.

Semiconductor diode structure 310 includes first and second doped semiconductor layers 311 and 312, respectively, and an active layer 314 therebetween. In many examples, first semiconductor layer 311 is an n-type semiconductor and second semiconductor layer 312 is a p-type semiconductor. Active layer 314 is arranged to emit output light at a nominal emission vacuum wavelength (λ ₀ ) due to current flow through device 300 . The emitted output light propagates within the diode structure 310. Diode structure 310 is typically arranged as a semiconductor light emitting diode (LED). Diode structure 310 (and layers 311/312/314) typically comprises one or more doped or undoped Group III-V, II-VI, or IV semiconductor materials, or alloys or mixtures thereof. can do. Common materials used include group III nitride materials (e.g., for emission in the near UV and blue portions of the optical spectrum) and (e.g., for emission in the yellow, red, and near IR portions of the optical spectrum). ) for emission from parts) and group III phosphide materials; One or more other suitable materials may be used. Active layer 314 may be arranged in any suitable manner to emit light in response to current flowing through diode structure 310. The active layer may include, for example, one or more pn junctions, one or more quantum wells, one or more multi-quantum wells, or one or more quantum dots. In some examples, the nominal emission vacuum wavelength (λ ₀ ) may be greater than about 0.20 μm, greater than about 0.40 μm, greater than about 0.8 μm, less than about 10 μm, less than about 2.5 μm, or less than about 1.0 μm.

A surface-lattice-resonance (SLR) structure 320 is positioned against the back surface of the second semiconductor layer 312 and includes an index-matching layer 320a, a low-index layer 320b, and scattering elements ( 320c). Index-matching layer 320a includes a substantially transparent dielectric material positioned against the rear surface of second semiconductor layer 312 and has an effective refractive index substantially equal to the effective refractive index of second semiconductor layer 312. . Low-index layer 320b includes a substantially transparent dielectric material positioned against the back surface of index-matching layer 320a and has an effective index of refraction that is lower than the effective index of refraction of index-matching layer 320a. Scattering elements 320c are located on or within index-matching layer 320a. The second semiconductor layer 312 is sufficiently thin such that the SLR structure 320 is within near-field proximity to the active layer 314 for the vacuum wavelength λ ₀ . In some examples, the distance between active layer 314 and SLR structure 320 may be less than about λ ₀ /n, less than about λ ₀ /2n, less than about λ ₀ /4n, or less than about λ ₀ /10n, where , n is the effective refractive index of the second semiconductor layer 312.

At least a portion of the front surface of the first semiconductor layer 311 is arranged as a device exit surface 317 that is in contact with the external medium 99 (eg, ambient air or sapphire substrate). At least a portion of the output light that propagates perpendicularly within the diode structure 310 with respect to the device exit surface 317 and is incident within the diode structure 310 on the device exit surface 317 is the device output light. is released. In some examples, the entire front surface of first semiconductor layer 311 may be arranged as device exit surface 317 . In other examples, only a first portion of the front surface of the first semiconductor layer 311 is arranged as the device output surface 317 . In these examples, the second portion of the front surface of the first semiconductor layer 311 may be arranged to exhibit specular or non-specular internally reflective redirection of output light incident on the front surface from within the diode structure 300; ; Photons redirected by those parts can make another round trip through the diode structure 310.

Reflector 305 is positioned against the back surface of low-index layer 320b (i.e., SLR structure 320 is positioned between reflector 305 and the back surface of semiconductor layer 312). In some examples, reflector 305 may include a distributed Bragg reflector (DBR) or a dielectric multilayer reflector (MLR); In some examples, reflector 305 may include a metal layer (eg, aluminum, silver, or gold); In some examples, reflector 305 may include both a metal layer and a DBR or MLR, with the DBR or MLR between the metal layer and QGM structure 320. Some examples that include a metal layer (e.g., as an electrical contact, and in some examples also included within the reflector 305) may also include one or more electrically conductive vias 308. Each via 308 may be arranged as a localized circumscribed electrical conduction path through the SLR structure 320 between the metal layer and the second semiconductor layer 312. In some examples including vias 308, vias 308 may be connected directly to second semiconductor layer 312 (e.g., as in Figure 1A). In some other examples that include vias 308, device 300 includes a substantially transparent electrode between SLR structure 320 and the back surface of second semiconductor layer 312 (e.g., as in FIG. 1B). may include layer 309; Vias 308 provide an electrically conductive path between the metal layer and the semiconductor layer 312 by connecting to the electrode layer 309, which is in direct contact with the semiconductor layer 312. Transparent electrode layer 309 may include one or more of indium tin oxide (ITO), indium zinc oxide, or one or more other transparent conductive oxides.

To form the SLR structure 310, doped or undoped silicon; one or more doped or undoped group III-V, II-VI, or IV semiconductors; Doped or undoped silicon oxide, nitride, or oxynitride; One or more doped or undoped metal oxides, nitrides, or oxynitrides; one or more optical glasses; Alternatively, any suitable dielectric material may be used, including one or more of one or more doped or undoped polymers. In some examples, SLR structure 320 may include a niobium oxide index-matching layer 320a (e.g., index matched to GaN semiconductor layer 312) and a silica low-index layer 320b.

Device 300 of the present invention may (e.g., (i)) extend from the surface of index-matching layer 320a into or across index-matching layer 320a (e.g., as in FIGS. 1A and 1B); , (ii) extends from the surface of the index-matching layer 320a into the low-index layer 320b, (iii) spans the interface between the index-matching layer 320a and the cladding layer 320b, or ( iv) further comprising a plurality of optical scattering elements 320c arranged on or within the index-matching layer 302a of the SLR structure 320 (fully embedded within the index-matching layer 320a). The collective structural arrangement of second semiconductor layer 312, index-matching layer 320a, low-index layer 320b, and scattering elements 320c supports one or more surface-lattice-resonance (SLR) modes. do. Coupling of output light to one or more of the SLR modes results in a non-zero fraction of the output light propagating within device 300 being redirected to propagate vertically toward device exit surface 317 . Advantageously, the fraction of laterally propagating output light emitted from the active layer 314 can be redirected to propagate vertically toward the device exit surface 317 through coupling to such SLR modes. The near-field proximity of the SLR structure 320 to the active layer 314, and the spatial overlap of the dissipative portions of the SLR modes supported by the SLR structure 320 onto the active layer 314, determines that one of the SLR modes It is possible to improve the coupling of the emitted output light to the above. An additional effect of the scattering elements 320c is that light emitted to propagate laterally (i.e., out of the escape cone) is redirected during a round trip through the diode structure 300 and then vertically (i.e., within the escape cone) on a subsequent round trip. ) increases the probability of transmission through the exit surface 317 with a smaller median number of round trips by increasing the probability of propagation.

In some examples, scattering elements 320c may include one or more volumes of dielectric material within one or more corresponding layers of SLR structure 320; The dielectric material of each of those scattering elements 320c will differ from the material of the corresponding layer of the SLR structure with respect to the refractive index. In some examples, scattering elements 320c may include one or more volumes of metallic material (eg, aluminum, silver, or gold) within one or more corresponding layers of SLR structure 320. In some examples, the scattering elements 320c may be (e.g., (i) Light-emitting Light-emitting Light-emitting Light-emitting Light-emitting Light-emitting Light-emitting Light-Emitting Light Light-emitting Light-emitting Light-Emitting Light Light-emitting Light-Emitting Light Light-emitting Light-Emitting Light Light-emitting Light-emitting Light-emitting Light-Emitting Element (e.g., “Light-emitting Light-emitting Light-emitting Light-emitting Light-emitting Light-Emitting Light-emitting Light-emitting Light-emitting Light-emitting Light-emitting Light-emitting Light-emitting Light-emitting Light-emitting Element” (e.g., “Light-emitting Light-emitting Light-emitting Light-emitting Light-emitting Light-emitting Light-emitting Light-emitting Light-emitting Light-emitting Light-Emitting Light-emitting Light-emitting Light-emitting Light-emitting Element”, filed December 14, 2020, under the names of (i) Antonio Lopez-Julia, Venkata Ananth Tamma, Aimi Abass, and Philipp Schneider. US Non-Specular Application No. 17/121,014, entitled “device with internal non-specular light redirection and anti-reflective exit surface,” and (ii) 6, 2021 in the names of Antonio Lopez-Julia, Venkata Ananth Tamma, and Aimi Abass U.S. Provisional Application No. 63/197,648, entitled “Light-emitting device with internal non-specular light redirection and position-dependent reflection, transmission, or redirection,” filed Mar. 7—both of which are incorporated herein by reference. may include one or more nano-antennas or one or more meta-atoms or meta-molecules within one or more layers of the SLR structure 320 (including as disclosed in their entirety herein). In some examples, QGM structure 320 may include a niobium oxide index-matching layer 320a, a silica low-index layer 320b, and aluminum scattering elements 320c.

In some examples, the size of scattering elements 320c or the spacing between them may be less than about λ ₀ /n, less than about λ ₀ /2n, less than about λ ₀ /4n, or less than about λ ₀ /10n, and n is the effective refractive index of the second semiconductor layer 312. In some examples, scattering elements 320c include one or more metals or metal alloys; Doped or undoped silicon; one or more doped or undoped group III-V, II-VI, or IV semiconductors; Doped or undoped silicon oxide, nitride, or oxynitride; One or more doped or undoped metal oxides, nitrides, or oxynitrides; one or more optical glasses; or one or more doped or undoped polymers. In some examples, scattering elements 320c may be arranged within one or more corresponding layers of SLR structure 320 as a corresponding periodic array within a corresponding layer of SLR structure 320; Such arrays can be of any suitable type or arrangement, such as rectangular, hexagonal, or triangular arrays. In other examples, scattering elements 320c may be arranged within one or more corresponding layers of SLR structure 320 in a random or aperiodic arrangement.

Design or optimization of diode structure 310 and SLR structure 320 is performed (by calculation, simulation, or iterative design/manufacture/test of primitives or test devices) based on one or more selected figures of merit (FOM). It can be. FOMs often considered are, for example: (i) Purcell factor (Pf; relative spontaneous emission rate influenced by the environment; Pf defines the total emitted power normalized to the emission in a homogeneous medium); (ii) total radiated emission (tot.rad.em. or Rad tot; total (far-field) emitted power of the source reaching the escape surface); (iii) radiative emission (angle) (Rad _{CriticalAngle} ; fraction of total radiative emission limited to a particular escape cone, e.g., 24.2° for GaN-Air or 46.8° for GaN-Sapphire); or (iv) radiation efficiency (Rad eff; ratio Rad tot/Pf; which quantifies the ability of the system to radiate power into the escape surface with minimal absorption losses). Instead or in addition, reductions in cost or manufacturing complexity can be utilized as FOM in a design or optimization process. Optimization for one FOM may result in suboptimal values for one or more other FOMs. Devices that are not necessarily fully optimized may nonetheless provide acceptable improvements in one or more FOMs; It is noted that such partially optimized devices are within the scope of this disclosure or the appended claims.

Devices 300 of the invention arranged according to FIG. 1A or 1B may be optimized to exhibit improvements with respect to one or more of the FOMs mentioned above. The near-field proximity of the SLR structure 320 to the active layer 314, and the spatial overlap of the dissipative portions of the SLR modes supported by the SLR structure 320 onto the active layer 314 can enhance the spontaneous emission rate. It is believed that SLR can change the spatial distribution of such emissions so that they are more vertically oriented than non-existent emissions. Together, these effects can result in a larger fraction of the emitted light propagating within a given escape cone. The multiple layer thicknesses and size/shape/arrangement of scattering elements 320c within the SLR structure 320 also provide a number of parameters that can be tuned in a given optimization process to achieve the conventional devices of FIGS. 3 and 4 . Provides opportunities for improvements over others.

In the example of Figure 2A, diode structure 310 is a GaN LED (layers 312 and 314 are 50 nm thick) and index-matching layer 320a is niobium oxide (GaN layer 312) is 50 nm thick. ), the low-index layer 320b is silica with a thickness of 450 nm, and the reflector 305 is a silver layer. The electrode layer 309 is ITO and has a thickness of 20 nm. Scattering elements 320c are aluminum nanoantennas 50 nm high and 60 nm wide and extend fully through niobium oxide layer 320a. Scattering elements 320c are arranged on a 184 nm grid. A plot of angle-dependent radiation intensity (not sine-corrected) for the device of FIG. 2A is shown in FIG. 2B. The device of FIG. 2A exhibits strongly enhanced emission near zero degrees (i.e., substantially perpendicular to the device exit surface 317), and reduced emission at other angles. Such behavior may result in a relatively high fraction of the emitted output light propagating within the escape cone prior to its initial encounter with the device exit surface 317. Other arrangements and material combinations may be used, optimized with respect to any one or more selected FOM.

More generally, in some examples of fully or partially optimized light emitting devices 300 of the present invention, the near-field proximity of the SLR structure 320 to the active layer 314, and the structural arrangement of the SLR structure 320 can result in device 300 exhibiting a Purcell factor greater than about 1.01, greater than about 1.02, greater than about 1.03, greater than about 1.04, greater than about 1.05, or even higher. More generally, in some examples of fully or partially optimized light emitting devices 300 of the present invention, the near-field proximity of the SLR structure 320 to the active layer 314, and the structural arrangement of the SLR structure 320 Within the escape cone defined by the interface between the first semiconductor layer 311 and the external medium 99 (e.g., ambient air), greater than about 0.13, greater than about 0.14, greater than about 0.15, greater than about 0.16, about This may result in the fraction of output light propagating towards the front surface of the first semiconductor layer 311 within the diode structure 310 being greater than 0.17, or even higher. More generally, in some examples of fully or partially optimized light emitting devices 300 of the present invention, the near-field proximity of the SLR structure 320 to the active layer 314, and the structural arrangement of the SLR structure 320 Silver, within the escape cone defined by the interface between the first semiconductor layer 311 and the substantially transparent solid medium 99 (e.g., silicon or sapphire), is greater than about 0.35, greater than about 0.40, or even higher. , may result in the fraction of output light propagating towards the front surface of the first semiconductor layer 311 within the diode structure 310.

In some examples, one or both of the SLR structure 320 or device exit surface 317 may cause device 300 to emit a diode structure ( 310) may be arranged to indicate an average total number of internal redirections and internal reflections per photon of output light that is less than 30, less than 20, less than 10, or less than 5. In some examples, light-emitting device 300 may exhibit a photon extraction efficiency greater than about 80.%, greater than about 90.%, or greater than about 95.%. In some examples, the SLR structure 320, or the SLR structure 320 with a metal layer 305 on its rear surface, is greater than about 80.%, greater than about 85.%, greater than about 90.%, or It can exhibit a reflectance exceeding about 95.%. In some examples, the SLR structure 320, or the SLR structure 320 with a metal layer 305 on its back surface, has a radial power ratio of less than about 20.%, about 10.%, to the output light incident on it. %, less than about 5.0 %, less than about 2.0 %, or less than about 1.0 %.

In some examples, the arrangement of device exit surface 317 may include an external medium 99 that directly contacts at least a portion of the front surface of first semiconductor layer 311 . In some other examples, device exit surface 317 contacts external medium 99 such that the device exit surface 317 is front-surface for output light incident perpendicularly thereon from within diode structure 310. An anti-reflection layer or coating ( 318) may be included. In some examples, anti-reflection layer or coating 318 may include a single-layer quarter wave dielectric thin film or a multi-layer dielectric thin film; In some examples, anti-reflective layer or coating 318 may include an array of nano-antennas, meta-atoms, or meta-molecules; In some examples, anti-reflection layer or coating 318 may include a moth-eye structure or an index-gradient film. In some examples, the reflectivity of device exit surface 317 facing external medium 99 may be less than about 10.%, less than about 5.%, less than about 2.0%, less than about 1.0%, or less than about 0.5%. In some examples, the anti-reflection layer or coating is doped or undoped silicon oxide, nitride, or oxynitride; One or more doped or undoped metal oxides, nitrides, or oxynitrides; one or more optical glasses; or one or more doped or undoped polymers. In some examples, external medium 99 may be substantially solid and include one or more metal or semiconductor oxides, oxynitrides, or nitrides, one or more doped or undoped silicon, or one or more doped or undoped polymers. It may contain one or more substances; In some other examples, external medium 99 may include vacuum, air, a gaseous medium, or a liquid medium.

In some examples, a method for manufacturing the light emitting device 300 of the present invention includes the steps of (A) forming a first semiconductor layer 311, an active layer 314, and a second semiconductor layer 312; (B) forming an SLR structure 320 on the back surface of the second semiconductor layer 312; and (C) forming a reflector 305 on the rear surface of the SLR structure 320. In some examples, a method for manufacturing the light emitting device 300 of the present invention includes the steps of (A) forming a first semiconductor layer 311, an active layer 314, and a second semiconductor layer 312; (B) forming an SLR structure 320 on the back surface of the second semiconductor layer 312; (C) forming a reflector (305) on the rear surface of the SLR structure (320); and (D) forming an anti-reflection layer or coating 318 on the device exit surface 317. Any suitable one or more material processing techniques or methodologies may be used, including but not limited to beam or vapor deposition, any type of lithography, epitaxy, nanoimprinting, film or layer growth, etc.

The method for operating the light emitting device 300 of the present invention includes the light emitting device 300 emitting device output light to propagate from the device emitting surface 317 within the external medium 99 abutting the device emitting surface 317. Thus, the step of supplying power to the light emitting device 300 may be included.

In addition to the foregoing, the following exemplary embodiments are within the scope of this disclosure or the appended claims:

Example 1. A semiconductor light emitting device comprising (a) a semiconductor diode structure comprising first and second doped semiconductor layers and an active layer between the back surface of the first semiconductor layer and the front surface of the second semiconductor layer—active layer is arranged to emit output light propagated within the diode structure at the nominal emission vacuum wavelength (λ ₀ ) due to current flow through the device; (b) a surface-lattice-resonance (SLR) structure positioned against the rear surface of the second semiconductor layer—the SLR structure is (i) positioned against the rear surface of the second semiconductor layer and positioned against the rear surface of the second semiconductor layer; (ii) an index-matching layer of a substantially transparent dielectric material having an effective refractive index substantially equal to the refractive index, (ii) a substantially transparent index-matching layer positioned against the rear surface of the index-matching layer and having an effective refractive index that is substantially lower than the effective refractive index of the index-matching layer; a low-index layer of a transparent dielectric material, and (iii) a plurality of scattering elements positioned on or within the index-matching layer, wherein the second semiconductor layer is configured such that the SLR structure operates at a vacuum wavelength (λ ₀ ). Thin enough to be within near-field proximity to the active layer for -; and (c) a reflector on the back surface of the SLR structure such that the SLR structure is between the reflector and the back surface of the semiconductor layer, and (d) at least a portion of the front surface of the first semiconductor layer is arranged as the device exit surface. , through this device exit surface, at least a portion of the output light that propagates perpendicularly within the diode structure with respect to the device exit surface and is incident on the device exit surface within the diode structure exits the diode structure as device output light, (e) The scattering elements are arranged such that the SLR structure supports one or more SLR modes, and the combination of output light for one or more of the SLR modes results in a non-zero fraction of the output light propagating within the device, including output light propagating laterally. This results in redirecting the propagation vertically towards the device emission surface.

Example 2. The device of Example 1, where the reflector comprises a distributed Bragg reflector or a dielectric multi-layer reflector.

Example 3. The device of Example 2, where the distributed Bragg reflector or dielectric multi-layer reflector is made of doped or undoped silicon; one or more doped or undoped group III-V, II-VI, or IV semiconductors; Doped or undoped silicon oxide, nitride, or oxynitride; One or more doped or undoped metal oxides, nitrides, or oxynitrides; one or more optical glasses; or one or more doped or undoped polymers.

Example 4. The device of any one of Examples 1-3, wherein the reflector includes a metal layer.

Example 5. The device of Example 4 further includes one or more electrically conductive vias, each via arranged as a localized circumscribed electrical conduction path through the SLR structure between the metal layer and the second semiconductor layer.

Example 6. The device of any one of Examples 4 or 5, wherein the metal layer includes one or more of aluminum, silver, or gold.

Example 7. The device of any one of Examples 1-6, further comprising a substantially transparent electrode layer between the SLR structure and the back surface of the second semiconductor layer.

Example 8 The device of Example 7 further includes a plurality of electrically conductive vias, each via arranged as a localized circumscribed electrical conduction path through the SLR structure between the metal layer and the transparent electrode layer.

Example 9. The device of any one of Examples 7 or 8, wherein the transparent electrode layer comprises one or more of indium tin oxide, indium zinc oxide, or one or more other transparent conductive oxides.

Example 10. The device of any one of Examples 1-9, wherein the distance between the active layer and the SLR structure is less than about λ ₀ /n, less than about λ ₀ /2n, less than about λ ₀ /4n, or about λ It is less than ₀ /10n, where n is the effective refractive index of the second semiconductor layer.

Example 11. The device of any one of Examples 1-10, where λ ₀ is greater than about 0.20 μm, greater than about 0.4 μm, greater than about 0.8 μm, less than about 10 μm, less than about 2.5 μm, or about 1.0 μm. It is less than.

Example 12. The device of any one of Examples 1-11, wherein the SLR structure includes doped or undoped silicon; one or more doped or undoped group III-V, II-VI, or IV semiconductors; Doped or undoped silicon oxide, nitride, or oxynitride; One or more doped or undoped metal oxides, nitrides, or oxynitrides; one or more optical glasses; or one or more doped or undoped polymers.

Example 13. The device of any one of Examples 1-12, wherein the scattering elements include one or more volumes of dielectric material in one or more corresponding layers of the SLR structure, wherein the dielectric of each of the scattering elements is The material differs from the material of the corresponding layer of the SLR structure with respect to its refractive index.

Example 14. The device of any one of examples 1-13, wherein the scattering elements include one or more volumes of metallic material in one or more corresponding layers of the SLR structure.

Example 15. The device of any one of Examples 1-14, wherein the scattering elements comprise one or more nano-antennas or one or more meta-atoms or meta-molecules in one or more layers of the SLR structure.

Example 16. The device of any one of Examples 1-15, wherein the size of the scattering elements or the spacing between the scattering elements is less than about λ ₀ /n, less than about λ ₀ /2n, less than about λ ₀ /4n. , or less than about λ ₀ /10n, where n is the effective refractive index of the second semiconductor layer.

Example 17. The device of any one of examples 1-16, wherein the scattering elements include one or more metals or metal alloys, doped or undoped silicon; one or more doped or undoped group III-V, II-VI, or IV semiconductors; doped or undoped silicon oxide, nitride, or oxynitride; One or more doped or undoped metal oxides, nitrides, or oxynitrides; one or more optical glasses; or one or more doped or undoped polymers.

Example 18. The device of any one of Examples 1-17, wherein the SLR structure includes a niobium oxide index-matching layer, a silica low-index layer, and aluminum scattering elements.

Example 19. The device of any one of Examples 1-18, wherein the scattering elements are arranged on or in the index-matching layer as a periodic array.

Example 20. The device of example 19, where the periodic array is a rectangular, hexagonal, or triangular array.

Example 21. The device of any one of examples 1 to 20, wherein the scattering elements are arranged on or in the index-matching layer in a random or aperiodic arrangement.

Example 22. The device of any one of Examples 1-21, wherein the near-field proximity of the SLR structure to the active layer and the structural arrangement of the SLR structure are greater than about 1.01, greater than about 1.02, greater than about 1.03, This results in a Purcell factor greater than about 1.04, or greater than about 1.05.

Example 23. The device of any one of Examples 1-22, wherein the near-field proximity of the SLR structure to the active layer and the structural arrangement of the SLR structure comprises: abutting the first semiconductor layer and the front surface of the first semiconductor layer. Propagating toward the front surface of the first semiconductor layer within the diode structure within the escape cone defined by the interface between the external media, greater than about 0.13, greater than about 0.14, greater than about 0.15, greater than about 0.16, or greater than about 0.17. This results in the fraction of output light being

Example 24. The device of Example 23, wherein the external medium comprises ambient air.

Example 25. The device of any one of Examples 1-24, wherein the near-field proximity of the SLR structure to the active layer and the structural arrangement of the SLR structure comprises: abutting the first semiconductor layer and the front surface of the first semiconductor layer. This results in the fraction of output light propagating toward the front surface of the first semiconductor layer within the diode structure being greater than about 0.35 or greater than about 0.40 within the escape cone defined by the interface between the substantially transparent solid medium.

Example 26. The device of any one of Examples 1-25, wherein one or both the SLR structure or the device exit surface is such that the device emits the diode structure through the device exit surface after being emitted by the active layer. It is arranged to indicate an average total number of internal redirections and internal reflections per photon of output light that is less than 30, less than 20, less than 10, or less than 5.

Example 27. The device of any one of Examples 1-26, wherein the light emitting device exhibits a photon extraction efficiency that is greater than about 80.%, greater than about 90.%, or greater than about 95.%.

Example 28. The device of any one of Examples 1-27, wherein the SLR structure, or the SLR structure with a metal layer on its back surface, has greater than about 80.%, greater than about 85.%, greater than about 90.%. %, or greater than about 95. %.

Example 29. The device of any one of Examples 1-28, wherein the SLR structure, or the SLR structure with a metal layer on its back surface, emits less than about 20.% of the output light incident thereon. , represents an optical loss per pass that is less than about 10.%, less than about 5.%, less than about 2.0%, or less than about 1.0%.

Example 30. The device of any one of examples 1-29, wherein the arrangement of the device exit surface includes an external medium in direct contact with at least a portion of the front surface of the first semiconductor layer.

Example 31. The device of any one of Examples 1-29, wherein the device exit surface facing the external medium is front-surface, for output light incident perpendicularly thereon from within the diode structure. and an anti-reflection layer or coating so as to exhibit a reflectivity that is less than the Fresnel reflectance of the interface between the front surface of the first semiconductor layer and the external medium without the coating or layer.

Example 32. The device of Example 31, wherein the anti-reflection layer or coating comprises a single-layer quarter wave dielectric thin film or a multi-layer dielectric thin film.

Example 33. The device of example 31, where the anti-reflection layer or coating comprises an array of nano-antennas, meta-atoms, or meta-molecules.

Example 34. The device of Example 31, wherein the anti-reflection layer or coating comprises a moss-eye structure or a refractive index-gradient film.

Example 35. The device of any one of examples 31-34, wherein the reflectance of the device exit surface facing the external medium is less than about 10.%, less than about 5.%, less than about 2.0%, less than about 1.0%, or It is less than about 0.5%.

Example 36. The device of any one of Examples 31-35, wherein the anti-reflection layer or coating is selected from doped or undoped silicon oxide, nitride, or oxynitride; One or more doped or undoped metal oxides, nitrides, or oxynitrides; one or more optical glasses; or one or more doped or undoped polymers.

Example 37. The device of any one of Examples 31-36, wherein the front surface of the diode structure is positioned against an external medium, wherein the external medium is substantially solid and is one or more metal or semiconductor oxides, oxynitrides, or nitride, one or more doped or undoped silicon, or one or more doped or undoped polymers.

Example 38. The device of any one of Examples 31-36, wherein the external medium comprises a vacuum, air, a gaseous medium, or a liquid medium.

Example 39. The device of any one of Examples 1-38, wherein the entire front surface of the first semiconductor layer is arranged as the device exit surface.

Example 40. The device of any one of examples 1-38, wherein only the first portion of the front surface of the first semiconductor layer is arranged as the device output surface, and the second portion of the front surface of the first semiconductor layer is: The diode structure is arranged to exhibit specular or non-specular internally reflective redirection of output light incident on the front surface of the first semiconductor layer from within the diode structure.

Example 41. The device of any one of Examples 1-40, wherein the semiconductor diode structure includes a semiconductor light emitting diode.

Example 42. The device of any one of Examples 1-41, wherein the diode structure comprises one or more doped or undoped Group III-V, II-VI, or IV semiconductor materials, or alloys or mixtures thereof. Includes.

Example 43. The device of any one of Examples 1-42, wherein the active layer comprises one or more doped or undoped Group III-V, II-VI, or IV semiconductor materials, or alloys or mixtures thereof. Includes.

Example 44. The device of any one of Examples 1-43, wherein the active layer includes one or more p-n junctions, one or more quantum wells, one or more multi-quantum wells, or one or more quantum dots.

Example 45. A method for manufacturing the light emitting device of any one of Examples 1 to 44, the method comprising: (A) forming a first semiconductor layer, an active layer, and a second semiconductor layer; (B) forming an SLR structure on the back surface of the second semiconductor layer; and (C) forming a reflector on the rear surface of the SLR structure.

Example 46. A method for manufacturing the light emitting device of any one of Examples 31 to 44, the method comprising: (A) forming a first semiconductor layer, an active layer, and a second semiconductor layer; (B) forming an SLR structure on the back surface of the second semiconductor layer; (C) forming a reflector on the rear surface of the SLR structure; and (D) forming an anti-reflection layer or coating on the device exit surface.

Example 47. A method for operating the light-emitting device of any one of Examples 1-44, wherein the light-emitting device emits device output light to propagate from the device exit surface in an external medium adjoining the device exit surface. , including supplying power to the light emitting device.

The present disclosure is illustrative and not restrictive. Additional modifications will be apparent to those skilled in the art in light of this disclosure, and such further modifications are intended to be within the scope of this disclosure or the appended claims. Equivalents of the disclosed example embodiments and methods or modifications thereof are intended to fall within the scope of this disclosure or the appended claims.

In the foregoing detailed description, various features may be grouped together in various example embodiments for the purpose of streamlining the disclosure. This approach of the disclosure should not be construed as reflecting an intention to require more features than those explicitly recited in the corresponding claim. Rather, as the appended claims reflect, inventive subject matter may consist of less than all features of a single disclosed example embodiment. Accordingly, the present disclosure refers to an apparatus having any suitable subset of one or more features—features shown, described, or claimed in this application—including those subsets that may not be explicitly disclosed herein. It should be construed as implicitly disclosing certain embodiments. A “suitable” subset of features includes only those features that are neither incompatible nor mutually exclusive with respect to any other feature in the subset. Accordingly, the appended claims are hereby incorporated into the Detailed Description in their entirety, with each claim standing on its own as a separate disclosed embodiment. Moreover, each of the appended dependent claims should be construed as if it were subordinated to all non-conflicting preceding claims written in multiple dependent form solely for purposes of disclosure by the foregoing inclusion of the claims in the Detailed Description. It is further noted that the cumulative scope of the appended claims may, but need not, encompass the entire subject matter disclosed in this application.

For the purposes of this disclosure and the appended claims, the following interpretations shall apply. The words “comprising, including”, “having” and variations thereof, wherever they appear, should be construed as non-limiting terms and, unless explicitly stated otherwise, in the international application specification. , “at least” has the same meaning as when appended to each instance thereof. The indefinite article ("a") in the International Application Specification shall be construed as "one or more" unless "only one", "single", or other similar limitation is explicitly stated or implied in a particular context; ; Similarly, the definite article "the" in the international application specification means "the only one", "a single one of them", or "the" unless another similar limitation is explicitly stated or implied in a particular context. It should be interpreted as “one or more of”. The conjunction "or" is (i) otherwise explicitly stated, for example, by the use of "either...or...", "only one of", or similar language, or (ii) enumerated. Two or more of the alternatives presented should be interpreted inclusively, unless they are understood or disclosed (implicitly or explicitly) as incompatible or mutually exclusive within a particular context. In the latter case, “or” will be understood to include only those combinations that involve alternatives that are not mutually exclusive. In one example, “a dog or a cat”, “one or more of a dog or a cat”, and “one or more dogs or a cat” each mean one or more dogs without any cats, or one or more cats without any dogs, or one each It will be interpreted as above. In another example, “a dog, a cat, or a rat”, “one or more of a dog, a cat, or a rat”, and “one or more a dog, a cat, or a rat” each mean (i) one without any cats or rats; (ii) one or more cats without any dogs or rats, (iii) one or more rats without any dogs or cats, (iv) one or more dogs and one or more cats without any rats, (v) no cats. shall be construed as one or more dogs and one or more rats, (vi) one or more cats and one or more rats without any dogs, or (vii) one or more dogs, one or more cats, and one or more rats. In another example, “two or more dogs, cats, or rats” or “two or more dogs, cats, or rats” each means (i) one or more dogs and one or more cats without any rats, (ii) cats (iii) one or more cats and one or more rats without any dogs, or (iv) one or more dogs, one or more cats, and one or more rats; “3 or more”, “4 or more”, etc. will be interpreted similarly.

For the purposes of this disclosure or the appended claims, when terms such as “approximately equal,” “substantially equal,” “about or greater than,” “about or less than,” etc. are used in connection with numerical quantities, different interpretations may arise. Unless explicitly stated, standard conventions regarding measurement precision and number of significant digits will apply. For null quantities described by phrases such as “substantially prevented,” “substantially absent,” “substantially eliminated,” “equal to about zero,” “negligible,” etc., each such phrase means: For practical purposes in the context of the intended operation or use of a disclosed or claimed device or method, the overall behavior or performance of the device or method is such that the null quantity is actually completely eliminated, is exactly equal to zero, or is otherwise exactly nulled. If it were (null), it would indicate a case where the amount has been reduced or reduced to a degree that is no different from what would have occurred.

For the purposes of this disclosure and the appended claims, any labeling of elements, steps, limitations, or other portions of an embodiment, example, or claim (e.g., first, second, third, etc., a), (b), (c), etc., or (i), (ii), (iii), etc.) are for purposes of clarity only and imply any kind of ordering or precedence of the parts so labeled. It should not be interpreted as doing so. If any such ordering or priority is intended, it will either be explicitly stated in the examples, examples, or claims, or in some instances, it will be implied based on the specific content of the examples, examples, or claims. It may be enemy or inherent. In the appended claims, if the provisions of 35 USC § 112(f) are desired to apply in a device claim, the word “means” will appear in the device claim. If such provisions are desired to apply in a method claim, the words “steps for” will appear in the method claim. Conversely, if the words “means” or “steps for” do not appear in a claim, the provisions of 35 USC § 112(f) are not intended to apply to that claim.

If any one or more disclosures are incorporated herein by reference and such incorporated disclosures conflict, in part or in whole, with this disclosure or differ in scope from this disclosure, the extent of the conflict, the broader disclosure, or In accordance with the broader definitions of the terms, this disclosure takes precedence. If such included disclosures conflict with each other, in part or in whole, the disclosures of a later date shall control, depending on the degree of conflict.

Abstracts are provided when required as an aid to those searching for specific topics in the patent literature. However, the abstract is not intended to imply that any elements, features, or limitations mentioned in the abstract are necessarily covered by any particular claim. The scope of the subject matter covered by each claim will be determined solely by the recitation of that claim.

Claims (47)

As a semiconductor light emitting device,
A semiconductor diode structure comprising a first doped semiconductor layer and a second doped semiconductor layer, and an active layer between a rear surface of the first semiconductor layer and a front surface of the second semiconductor layer, the active layer comprising: arranged to emit output light propagated within said diode structure at a nominal emission vacuum wavelength (λ ₀ ) due to current flow through;
a surface-lattice-resonance (SLR) structure positioned against the rear surface of the second semiconductor layer—the SLR structure is (i) positioned against the rear surface of the second semiconductor layer and an index-matched layer of a substantially transparent dielectric material having an effective refractive index substantially equal to the effective refractive index of the index-matching layer, (ii) positioned against the rear surface of the index-matching layer; a lower-index layer of a substantially transparent dielectric material having a lower effective refractive index, and (iii) a plurality of scattering elements positioned on or within the index-matching layer, the second semiconductor layer is sufficiently thin such that the SLR structure is within near-field proximity to the active layer for the vacuum wavelength (λ ₀ ); and
reflector—the reflector is on the back surface of the SLR structure such that the SLR structure is between the reflector and the back surface of the semiconductor layer—
Includes,
At least a portion of the front surface of the first semiconductor layer is arranged as a device exit surface, through which the device exit surface propagates perpendicularly within the diode structure with respect to the device exit surface and within the diode structure. At least a portion of the output light incident on the diode structure exits the diode structure as device output light,
The scattering elements are arranged such that the SLR structure supports one or more SLR modes, and the combination of output light for one or more of the SLR modes results in output propagating within the device, including laterally propagating output light. A device that results in redirecting a non-zero fraction of light to propagate perpendicularly toward the device exit surface. According to paragraph 1,
The device of claim 1, wherein the reflector comprises a distributed Bragg reflector or a dielectric multi-layer reflector. According to paragraph 2,
The distributed Bragg reflector or the dielectric multi-layer reflector may include doped or undoped silicon; one or more doped or undoped group III-V, II-VI, or IV semiconductors; Doped or undoped silicon oxide, nitride, or oxynitride; One or more doped or undoped metal oxides, nitrides, or oxynitrides; one or more optical glasses; or one or more doped or undoped polymers. According to paragraph 1,
The device of claim 1, wherein the reflector includes a metal layer. According to paragraph 4,
The device further comprising one or more electrically conductive vias, each via arranged as a localized circumscribed electrical conduction path through the SLR structure between the metal layer and the second semiconductor layer. According to paragraph 4,
The device of claim 1, wherein the metal layer includes one or more of aluminum, silver, or gold. According to paragraph 1,
The device further comprising a substantially transparent electrode layer between the SLR structure and the back surface of the second semiconductor layer. In clause 7,
The device further comprising a plurality of electrically conductive vias, each via arranged as a localized circumscribed electrical conduction path through the SLR structure between a metal layer and the transparent electrode layer. In clause 7,
The device of claim 1, wherein the transparent electrode layer comprises one or more of indium tin oxide, indium zinc oxide, or one or more other transparent conductive oxides. According to paragraph 1,
The device of claim 1, wherein the distance between the active layer and the SLR structure is less than about λ ₀ /n, where n is the effective refractive index of the second semiconductor layer. According to paragraph 1,
λ ₀ is greater than about 0.20 μm and less than about 10 μm. According to paragraph 1,
The SLR structure may include doped or undoped silicon; one or more doped or undoped group III-V, II-VI, or IV semiconductors; Doped or undoped silicon oxide, nitride, or oxynitride; One or more doped or undoped metal oxides, nitrides, or oxynitrides; one or more optical glasses; or one or more doped or undoped polymers. According to paragraph 1,
The scattering elements include one or more volumes of dielectric material in one or more corresponding layers of the SLR structure, wherein the dielectric material of each of the scattering elements has a refractive index relative to the material of the corresponding layer of the SLR structure. Different devices. According to paragraph 1,
The device of claim 1, wherein the scattering elements comprise one or more volumes of metallic material in one or more corresponding layers of the SLR structure. According to paragraph 1,
The device of claim 1, wherein the scattering elements comprise one or more nano-antennas or one or more meta-atoms or meta-molecules in one or more layers of the SLR structure. According to paragraph 1,
The device of claim 1, wherein the size of the scattering elements or the spacing between the scattering elements is less than about λ ₀ /n, where n is the effective index of refraction of the second semiconductor layer. According to paragraph 1,
The scattering elements may include one or more metals or metal alloys, doped or undoped silicon; One or more doped or undoped group III-V, II-VI, or IV semiconductors; Doped or undoped silicon oxide, nitride, or oxynitride; One or more doped or undoped metal oxides, nitrides, or oxynitrides; one or more optical glasses; or one or more doped or undoped polymers. According to paragraph 1,
The device of claim 1, wherein the SLR structure includes a niobium oxide index-matching layer, a silica low-index layer, and aluminum scattering elements. According to paragraph 1,
The device of claim 1, wherein the scattering elements are arranged on or in the index-matching layer as a periodic array. According to clause 19,
The device of claim 1, wherein the periodic array is a rectangular, hexagonal, or triangular array. According to paragraph 1,
The device of claim 1, wherein the scattering elements are arranged on or in the index-matching layer in a random or aperiodic arrangement. According to paragraph 1,
The near-field proximity of the SLR structure to the active layer, and the structural arrangement of the SLR structure, result in the device exhibiting a Purcell factor greater than about 1.01. According to paragraph 1,
The near-field proximity of the SLR structure to the active layer, and the structural arrangement of the SLR structure, within an escape cone defined by the interface between the first semiconductor layer and the external medium abutting the front surface of the first semiconductor layer. resulting in a fraction of output light propagating toward the front surface of the first semiconductor layer within the diode structure being greater than about 0.13. According to clause 23,
The device of claim 1, wherein the external medium comprises ambient air. According to paragraph 1,
The near-field proximity of the SLR structure to the active layer, and the structural arrangement of the SLR structure, are defined by an interface between the first semiconductor layer and a substantially transparent solid medium abutting the front surface of the first semiconductor layer. Resulting in a fraction of output light propagating within the escape cone toward the front surface of the first semiconductor layer within the diode structure being greater than about 0.35. According to paragraph 1,
One or both of the SLR structure or the device exit surface may cause the device to undergo internal redirections per photon of output light that are less than 30 times before exiting the diode structure through the device exit surface after being emitted by the active layer, and A device arranged to indicate an average total number of internal reflections. According to paragraph 1,
The device of claim 1, wherein the light emitting device exhibits a photon extraction efficiency greater than about 80.%. According to paragraph 1,
The device of claim 1, wherein the SLR structure, or the SLR structure with a metal layer on its back surface, exhibits a reflectivity greater than about 80.%. According to paragraph 1,
The device of claim 1, wherein the SLR structure, or the SLR structure having a metal layer on its back surface, exhibits an optical loss per pass of less than about 20.% for output light incident on the SLR structure. According to paragraph 1,
The device wherein the arrangement of the device exit surface includes an external medium in direct contact with at least a portion of the front surface of the first semiconductor layer. According to paragraph 1,
The device exit surface is in contact with an external medium, and for output light incident perpendicularly on the device exit surface from within the diode structure, the device exit surface is formed without a front-surface coating or layer of the first semiconductor layer. A device comprising an anti-reflection layer or coating to exhibit a reflectivity that is less than the Fresnel reflectance of the interface between the front surface and the external medium. According to clause 31,
The device of claim 1, wherein the anti-reflection layer or coating comprises a single-layer quarter wave dielectric thin film or a multi-layer dielectric thin film. According to clause 31,
The device of claim 1, wherein the anti-reflection layer or coating comprises an array of nano-antennas, meta-atoms, or meta-molecules. According to clause 31,
The device of claim 1, wherein the anti-reflection layer or coating comprises a moth-eye structure or an index-gradient film. According to clause 31,
The device of claim 1, wherein the reflectance of the device exit surface facing the external medium is less than about 10.%. According to clause 31,
The anti-reflection layer or coating may be made of doped or undoped silicon oxide, nitride, or oxynitride; One or more doped or undoped metal oxides, nitrides, or oxynitrides; one or more optical glasses; or one or more doped or undoped polymers. According to clause 31,
The front surface of the diode structure is positioned against the external medium, the external medium being substantially solid and comprising one or more metal or semiconductor oxides, oxynitrides, or nitrides, one or more doped or undoped silicon, or one or more metal or semiconductor oxides, oxynitrides, or nitrides; A device comprising one or more of one or more doped or undoped polymers. According to clause 31,
The device wherein the external medium includes vacuum, air, a gaseous medium, or a liquid medium. According to paragraph 1,
The entire front surface of the first semiconductor layer is arranged as the device exit surface. According to paragraph 1,
Only a first part of the front surface of the first semiconductor layer is arranged as the device output surface, and a second part of the front surface of the first semiconductor layer is arranged on the front surface of the first semiconductor layer from within the diode structure. A device arranged to exhibit specular or non-specular internally reflective redirection of incident output light. According to paragraph 1,
The device of claim 1, wherein the semiconductor diode structure includes a semiconductor light emitting diode. According to paragraph 1,
The device of claim 1, wherein the diode structure comprises one or more doped or undoped Group III-V, II-VI, or IV semiconductor materials, or alloys or mixtures thereof. According to paragraph 1,
The device of claim 1, wherein the active layer comprises one or more doped or undoped Group III-V, II-VI, or IV semiconductor materials, or alloys or mixtures thereof. According to paragraph 1,
The device of claim 1, wherein the active layer includes one or more pn junctions, one or more quantum wells, one or more multi-quantum wells, or one or more quantum dots. A method for manufacturing a light-emitting device, comprising:
The light emitting device is the light emitting device of any one of claims 1 to 44, the method comprising: (A) forming a first semiconductor layer, an active layer, and a second semiconductor layer; (B) forming the SLR structure on the back surface of the second semiconductor layer; and (C) forming a reflector on the rear surface of the SLR structure. A method for manufacturing a light-emitting device, comprising:
The light emitting device is the light emitting device of any one of claims 31 to 44, the method comprising: (A) forming a first semiconductor layer, an active layer, and a second semiconductor layer; (B) forming the SLR structure on the back surface of the second semiconductor layer; and (C) forming a reflector on the rear surface of the SLR structure; and (D) forming an anti-reflective layer or coating on the device exit surface. As a method for operating a light-emitting device,
The light-emitting device is the light-emitting device of any one of claims 1 to 44, and the method comprises: causing the light-emitting device to emit device output light to propagate from a device emitting surface in an external medium abutting the device emitting surface, A method comprising powering the light emitting device.

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