Systems and methods for advanced thermophotovoltaic systems for wireless power transfer

Abstract

Provided herein are systems and methods for a thermophotovoltaic (TPV) system integrating advanced monolithic absorber / emitter structures for wireless power transmission. The TPV system efficiently converts wireless beamed power, delivered through various forms of electromagnetic radiation including laser, microwave, and solar, into electric power. The monolithic structures, comprising multilayered thin films substrates, are designed to withstand high temperatures and provide spectral selectivity. The monolithic structure enhances the efficiency and durability of TPV systems, making them ideal for both terrestrial and aerospace applications. The system also features an optical cavity and an origami-based radiative cooling structure for improved performance.

Description

SYSTEMS AND METHODS FOR ADVANCED THERMOPHOTOVOLTAIC SYSTEMS FOR WIRELESS POWER TRANSFERTechnical Field

[0001] The embodiments disclosed herein relate to wireless power transfer, and more specifically to novel, sustainable, sturdy, and monolithic absorbers / emitters integrated into or embedded within thermophotovoltaic (TPV) systems that function as receivers in wireless power transfer systems, which transfer power via electromagnetic fields.Introduction

[0002] Wireless power transmission has gained popularity for both terrestrial and aerospace applications, primarily driven by the escalating costs associated with transporting conventional fuels for satellites, drones, and other aerospace systems. For example, drones are often powered by batteries, however, batteries are characterized by relatively low power densities, and they increase the overall weight of flying objects. Thermophotovoltaic (TPV) technology, with its impressive system efficiencies reaching approximately 50%, presents a promising avenue for power generation by converting heat from any high-temperature source into electric power. Moreover, TPV systems are lightweight and have no moving components. TPV technology has emerged as a key player in clean energy storage as well.

[0003] Wireless power transmission equipped with robust monolithic absorbers / emitters- based TPV technology has the potential to achieve numerous advantages and higher efficiencies compared to traditional wireless power transmission systems.

[0004] TPV systems could also benefit from an absorber / emitter which can operate under high-temperature cyclic conditions for extended periods of time, much longer than any reported in the literature to date.

[0005] The technology is relatively new and, therefore, the potential is yet to be fully explored. Accordingly, there is a need for new and improved multisource TPV systems which enable multiple sources of thermal energy to efficiently act as inputs to a single TPV system.Summary

[0006] Provided herein is a thermophotovoltaic (TPV) system including a monolithic-absorber and emitter configured to selectively capture specific wavelengths of laser sources, solar radiation and / or any electromagnetic and acoustic wave, and at least one photovoltaic PV) cell, wherein the absorber is optimized to absorb radiation at a wavelength of an incoming wireless power beam, and wherein the emitter is optimized to emit radiation at a wavelength matched with a bandgap of the PV cell to convert thermal emission heat to electricity.

[0007] The monolithic absorber and emitter may include planar multilayered structures fabricated on different substrates and thin films with different thicknesses are deposited onto the substrate to form a spectrally selective and durable absorber and emitter.

[0008] The thin films may be selected from materials durable in high temperatures, including at least on of: Ta, Ru, Re, Os, Nb, Mo, Ir, Hf, WSi2, MoSF2, ZrB2, TiB2, HfB2, LaB6, ZrC, VC, TiC, TaC, Ta2C, NbC, SiC, B4C, a-C, ZrN, VN, TiN, NbN, HfN, ScN, BN, AIN, ZrO2, YSZ, Ta2O5, HfO2, Cr2Os, Yb2Os, Y2OS, SC2OS, LU2OS, Gd2Os, Dy2Os, BeO, AI2Os, MgAI2O4.

[0009] The TPV system may further include an optical cavity in various forms of ellipsoids or geometric equivalents, wherein the optical cavity.

[0010] The optical cavity may include an ellipsoidal cavity with the absorber / emitter spanning the foci area, and a highly specular reflective coating on the inner surface in the infrared (IR) region.

[0011] The absorber / emitter may be configured to receive radiation from multiple sources including: laser power beaming, microwave, or radiofrequency (RF) power beaming, electromagnetic power delivered through optic cables, concentrated solar radiation, solar irradiance, fuels, waste heat, and nuclear energy sources.

[0012] The absorber and emitter may operate under high-temperature cyclic conditions for extended periods of time.

[0013] The PV cell may be passively cooled by an origami-based radiative cooling structure.

[0014] The TPV system may be configured for wireless power transmission (WPT).

[0015] The TPV system may further comprise a radiative cooling structure positioned under the PV cell.

[0016] The radiative cooling structure may further comprise a square cooling multi-material plate with dimensions of 24 cm x 24 cm x 0.5 mm, wherein the cooling plate material varies horizontally with an inner surface of copper / aluminum and an outer surface of aluminum / copper, joined by highly conductive thermal graphite.

[0017] The cooling plate geometry may be varied by changing the material along a first direction while maintaining a constant volume in order to enhance thermal dissipation, wherein the first direction is one of horizontal, vertical, and planar.

[0018] The cooling plate geometry may be varied by changing the material in both a first direction and a second direction to optimize the temperature distribution and heat dissipation across the structure.

[0019] The monolithic absorber and emitter may further comprise an optical filter on top of the PV cell.

[0020] Provided herein is a method of forming a multilayered monolithic absorber and emitter for use in a TPV system, including depositing at least one layer of a coating onto a monolithic substrate which is configured to absorb photons and emit heat, wherein the coating determines a spectral selectivity and a durability of the absorber and emitter.

[0021] Other aspects and features will become apparent to those ordinarily skilled in the art, upon review of the following description of some exemplary embodiments.Brief Description of the Drawings

[0022] The drawings included herewith are for illustrating various examples of articles, methods, and apparatuses of the present specification. In the drawings:

[0023] Figure 1 is a block diagram of a thermophotovoltaic cell receiving energy from a thermal emitter, showing the four pathways of photons, according to the state of the art;

[0024] Figure 2 is a Venn diagram of different criteria for achieving highly efficient, sustainable, and durable monolithic absorber / emitter TPV-based wireless power beaming;

[0025] Figure 3 shows a wireless power beaming TPV system with monolithic absorber / emitter and a single heat source or multiple heat source(s);

[0026] Figure 4 shows an example of the monolithic absorber and emitter TPV system for wireless power beaming, wherein the absorber is powered by incoming concentrated electromagnetic wave and combustion, and the PV cell is passively cooled by a multilayer and multi-material radiative cooling structure, according to an embodiment;

[0027] Figure 5 shows an example of a monolithic absorber and emitter TPV-based wireless power beaming system powered by multiple sources in an ellipsoidal optical cavity, according to an embodiment;

[0028] Figure 6 shows another example of a monolithic absorber and emitter TPV-based wireless power beaming system powered by multiple sources in an ellipsoidal optical cavity with a vacuum port, according to an embodiment;

[0029] Figures 7A, 7B, 7C show monolithic TPV systems that comprises a) a monolithic absorber / emitter in an oblate hemispheroidal, b) a monolithic absorber / emitter in an oblate ellipsoid optical cavity, both powered by beamed electromagnetic radiation, and c) a multisource configuration of a wireless power transmission system;

[0030] Figure 8 shows a sample configuration for the absorption section of a monolithic absorber / emitter TPV system, wherein aluminum nitride (AIN) is coated on a tungsten (W) substrate, along with the spectral solar emissive power as an example of an input heat sources;

[0031] Figure 9 shows normal-direction solar absorption as a function of the AIN thicknesses of the configuration of Figure 8;

[0032] Figure 10 shows a direct and circumsolar spectral solar irradiance and normal-direction spectral emission of an optimized ZrO2-based absorber with a coating thickness of 2.5 pm on tungsten substrate;

[0033] Figure 11 shows a normalized blackbody spectral emissive power at three temperatures, and normal direction spectral emittance of a sample monolithic emitter including AIN coating on tungsten with different thicknesses, wherein a bandgap of a GaSb PV cell is shown as a dashed line;

[0034] Figure 12 shows three indicator results for the AIN / W-based monolithic emitter at three emitter temperatures of Temper = 1500, 1900, and 2300 K, as a function of the AIN coating on W substrate;

[0035] Figure 13 shows an air-bridge configuration for a monolithic absorber / emitter which includes of an airgap sandwiched between tungsten substrate and a coating, wherein the W coating varies from a = 0 to a = 40 nm, and the thickness of the sir-bridge is d = 200 nm;

[0036] Figure 14 shows a different air-bridge configuration for a monolithic absorber / emitter which includes of an airgap sandwiched between tungsten substrate and coating, wherein the W coating varies from a = 0 to a = 10 nm, and the thickness of the air-bridge is d = 500 nm;

[0037] Figure 15 shows a SiO2 dielectric-bridge with three different thicknesses of d= 100, 300, and 500 nm for a constant value of the tungsten coating at a = 10 nm, wherein the dashed line is a bandgap of a GaSb PV cell;

[0038] Figure 16 shows a T-shaped configuration of a monolithic absorber / emitter, wherein the width and height of the pole of the T is 100 nm and the thickness of the top surface of the T is 10 nm;

[0039] Figure 17 shows measured absorption, reflection, and transmission of the monolithic absorber structure optimized to have the highest absorption for CO2 laser (A = 10.6 pm), wherein the coating material is AIN with optimized thickness of d = 4.5 pm;

[0040] Figure 18 shows a normalized blackbody spectral emissive power for four emitter temperatures of Temitter=1000, 1500, 1800, and 2200 K, and the spectral absorptivity of the optimized monolithic structure shown in Figure 16;

[0041] Figure 19 shows the rate of total emissive power (emission loss from topside surface) for the proposed structure in Figure 16 as a function of the emitter temperature;

[0042] Figure 20 shows a configuration with the addition of a thin layer of gold (d = 100nm) between the W substrate and AIN coating structure proposed in Figure 16 to further decrease the emission loss from the absorber;

[0043] Figure 21 shows the rate of total emissive power (emission loss from topside surface) for the proposed structure in Figure 19 as a function of the emitter temperature;

[0044] Figure 22 shows a dual-band absorption structure for CO2 laser (A = 10.6 pm) and Xenon Chloride laser (A = 10.6 pm), wherein the absorber is a bare AIN;

[0045] Figure 23A shows a total spectral emissive power (spectral emission loss toward upside of the absorber) for the structure shown in Figure 21 for four different emitter temperatures of Temitter—1000, 1500, 2000, 2500 K;

[0046] Figure 23B shows a rate of the total emission loss as a function of Temitter;

[0047] Figure 24 shows simulation results for cell temperature as a function of the thickness of the copper radiative cooling plate beneath a PV cell;

[0048] Figure 25 shows simulation results for cell temperature as a function of the cross- sectional area for the copper radiative cooling plate beneath the PV cell;

[0049] Figure 26 shows a temperature gradient across the radiative cooling structure of Figure 24 for different material arrangement in the planar direction;

[0050] Figure 27 shows a temperature gradient across the radiative cooling structure of Figure 24 for different material compositions in the planar and vertical directions;

[0051] Figure 28A shows a fabricated multi-material radiative cooling structure with copper and aluminum, and Figure 28B shows a temperature gradient recorded in six thermocouples located along the plate;

[0052] Figure 29 shows simulation results for the multi-material radiative cooling shown in Figure 28A, wherein temperature is plotted as a function of the plate arc-length from the center to the edge with different thermal conduction coefficient (he), and wherein the outer plate is Cu, the inner plate is Al, and the input power is 4 W;

[0053] Figure 30 shows simulation results for the multi-material radiative cooling shown in Figure 28A, wherein temperature is plotted as a function of the plate arc-length from the center to the edge with different thermal conduction coefficient (he), and wherein the outer plate is Cu, the inner plate is Al, and the input power is 5 W;

[0054] Figure 31 shows simulation results for the multi-material radiative cooling shown in Figure 28A, wherein temperature is plotted as a function of the plate arc-length from the center to the edge with different thermal conduction coefficient (he), and wherein the outer plate is Al, the inner plate is Cu, and the input power is 4 W;

[0055] Figure 32 shows simulation results for the multi-material radiative cooling shown in Figure 28A, wherein temperature is plotted as a function of the plate arc-length from the center to the edge with different thermal conduction coefficient (he), and wherein the outer plate is Al, the inner plate is Cu, and the input power is 5 W;

[0056] Figure 33 shows a cross-section of material locations and results of horizontal material sweep of the radiative cooling;

[0057] Figure 34 shows a temperature at center comparison for horizontal cases of the radiative cooling;

[0058] Figure 35 is an illustration of a vertical cross-section and results for vertical cases of the radiative cooling;

[0059] Figure 36 shows a temperature at center comparison for vertical cases of the radiative cooling;

[0060] Figure 37 shows a stationary configuration example of a monolithic absorber / emitter TPV-based WPT;

[0061] Figure 38 shows a mountable / portable / mobile configuration of a monolithic absorber / emitter TPV-based WPT, wherein the TPV-based WPT is mounted on a drone;

[0062] Figure 39 shows spectral absorptance for different single-layer substrates; and

[0063] Figure 40 shows the spectral absorptance of AIN coated on a W substrate for different thicknesses of the AIN coating thicknesses, wherein the red line shows the maximum absorptance.Detailed Description

[0064] Various apparatuses or processes will be described below to provide an example of each claimed embodiment. No embodiment described below limits any claimed embodiment and any claimed embodiment may cover processes or apparatuses that differ from those described below. The claimed embodiments are not limited to apparatuses or processes having all of the features of any one apparatus or process described below or to features common to multiple or all of the apparatuses described below.

[0065] The thermophotovoltaic (TPV) systems described herein aim to synergize wireless power transmission (WPT) and TPV technology to provide new methods with unique capabilities for transporting power. The system includes development of a monolithic absorber / emitter designed to selectively capture specific wavelengths of laser, microwave, RF, and / or solar radiation sources onto a TPV system. The combination of these two fields (TPV systems and monolithic absorber / emitters) provides a transformative solution that overcomes past limitations in wireless power transmission and unlocks new possibilities for energy-efficient aerospace missions.

[0066] Herein “monolithic” refers to the fact that the absorber / emitter behaves a s a single integrated component and does not have any mechanically separate parts (i.e., is not modular or assembled in pieces). That is, the absorbing portion and the emitting portion are not separate components. While the monolithic absorber / emitter is made of multiple thin dielectric and metallic film layers and substrate it is fabricated as a single, inseparable stack, using deposition techniques (e.g., sputtering, evaporation, MBE, ALD), and it operates as one functional block (absorber / emitter) with no moving or separable components. The absorber / emitter is self- contained and self-supporting within a TPV system. Therefore, “monolithic” refers to a multilayered one-dimensional photonic crystal structure (e.g., dielectric / metallic sandwich) that is fabricated as a single, integrated unit, serving as an absorber / emitter in a wireless power transmission system.

[0067] Herein, multilayered sandwiched planar structures are employed as the absorber / emitter to enhance the performance (e.g. spectral / directional selectivity), durability, and functionality of TPV systems that can withstand frequent thermal cycling and high temperatures for prolonged periods of time.

[0068] A “multilayer structure” in the context of selective absorbers and / or emitters refers to a stack of thin films composed of two or more materials — often dielectrics and / or metals — that are sequentially deposited on top of a substrate, such as tungsten. These layers are carefully engineered, typically with nanometer-scale thicknesses, to exploit optical interference effects that control how light is absorbed, transmitted, or reflected across different wavelengths.

[0069] "Sandwich", refers to how these multiple layers are arranged vertically, one on top of the other, forming a compact and unified block. For example, a common design might includealternating high- and low-refractive-index materials deposited on a reflective metal substrate, creating what’s known as a 1 D photonic crystal.

[0070] Even though the system has internal complexity, it is often referred to as a monolithic absorber / emitter if the entire multilayer stack is fabricated together and functions as a unified, inseparable structure.

[0071] In addition to the capability of the system to capture solar irradiance, absorbers / emitters are designed to receive radiation from lasers or transmitters operating at different wavelengths or frequencies. The absorber can be optimized to absorb radiation at the wavelength of the incoming wireless power beam. Currently, in laser-based wireless power transmission systems, radiation from lasers is directly incident onto photovoltaic (PV) cells. However, this restricts the wavelength of the transmitted radiation to values that can be converted to electric power within the PV cell. Alternatively, the absorber within a TPV system can be designed to receive radiation at almost any wavelength. Furthermore, using an absorber / emitter enables wireless power transmission at wavelengths that exhibit low atmospheric attenuation.

[0072] It is also possible to use power transmission sources that operate at wavelengths which exhibit low divergence. This increases the functionality of both wireless power transmission and TPV systems, providing new opportunities including advanced methods for powering space vehicles, unmanned aerial vehicles, and underwater vehicles.

[0073] Referring now to Figure 1 , the main components of prior art TPV systems are an emitter and a PV cell. A thermal emitter 110 emits thermal energy toward a PV cell 120. The PV cell 120 includes an optical filter 125 on a surface which receives photons from the thermal emitter 110. The energy of the photons is greater than the bandgap of the PV cell in order for excess energy to be converted to thermal energy to be used by the PV cell. The bandgap is the energy an excited charge carrier needs to receive from an absorbed photon to generate current and output power in a photovoltaic cell (PV). For example, a PV cell made of GaSb has a bandgap of 0.72 eV. The bandgap is a threshold energy. “In-band” photons have wavelengths low enough such that their energy is higher than the bandgap value and can be absorbed and converted to electrical energy by the PV cell.

[0074] The photons emitted by the thermal emitter have four possible outcomes. A portion of the photons are lost due to non-unity factor viewing (arrow 132). A portion of the photons are reflected back to the thermal emitter off of the optical filter as recycled photons (arrow 134). A portion of the photons are received within the PV cell 120 but lost through thermalization (arrow 136). And a final portion of the photons are received by the PV cell 120 and converted into an electric output (arrow 138). As not all photons are absorbed by the PV cell, nor are all photons absorbed by the cell converted to electric power, optimization of input of photons and the performance of the PV cell is important.

[0075] TPV systems achieve higher output power by simultaneously receiving power from multiple sources. A power output that is simultaneously powered by a power source “1” and apower source “2” is typically greater than the power output from the same TPV system when it is powered by only power source “1” or only power source “2”.

[0076] For example, combining solar and thermal energy to power a TPV system can lead to a higher energy conversion efficiency as compared to when the same TPV system is powered by the same solar and thermal energy sources separately at different times.

[0077] “Power beaming" is the transmission of energy using a directed electromagnetic beam. Lasers and microwaves have primarily been investigated for power beaming, although electromagnetic radiation at other wavelengths can be used.

[0078] Atmospheric attenuation can severely decrease the transmitted beam power, especially over the electromagnetic wavelength range used in laser power transmission. Transferring the electromagnetic wave in the form of a periodically pulsed power beam may alleviate atmospheric attenuation. Using electromagnetic wavelengths for which the atmosphere is transparent, or has a low absorption coefficient, also mitigates atmospheric attenuation.

[0079] In typical TPV systems, as shown in Figure 1 , both the absorber / emitter and PV cell are under vacuum. However, several advantages can be realized by placing the absorber / emitter under vacuum in a smaller compartment with windows. By removing the PV cell from the vacuum, a more effective cooling system can be used to reduce the temperature of the PV cells, which is important for realizing high efficiencies and extending their lifetime. Furthermore, the size and cost of the TPV system can be reduced by minimizing the volume of space under vacuum. It has previously been demonstrated that employing an ellipsoidal optical cavity allows the separation of the PV cell and the emitter. This design enables bringing the PV cell out of a vacuum without sacrificing the high view factor between the PV cell and emitter. This TPV system configuration can be used for the wireless transmission system.

[0080] In the systems described herein, multiple energy sources may be used to provide power to the TPV system, although at least one source is delivered in the form of electromagnetic radiation. Herein, beamed power may refer to different forms of directed electromagnetic radiation including, but not limited to, laser power beaming, optical power beaming, mm-wave power beaming electromagnetic power transmitted as microwave or RF power beaming, maser power beaming, electromagnetic power delivered through optic cables, and concentrated solar radiation. The power beam may be delivered as an electromagnetic pulse or as a periodically pulsed electromagnetic beam. Other sources of energy could include, but are not limited to, inductively coupled energy systems, magnetically coupled energy systems, solar irradiance, fuels, waste heat, stored heat in thermal batteries, geothermal, and nuclear energy sources. Multisource TPV systems have the potential to achieve higher efficiencies compared to traditional single-source TPV systems.

[0081] In one embodiment of the TPV system described herein, planar multilayered (sandwiched) monolithic structures are used to fabricate selective absorbers / emitters that can withstand high temperatures for prolonged periods of time. For example, different thin films withdifferent thicknesses are deposited on a tungsten (W) substrate to form the spectrally selective, and durable / robust emitter / absorber. Electromagnetic radiation powers a TPV system when it is incident onto an absorber that is thermally coupled to an emitter. Radiation from the emitter is converted to electric power in a PV cell within the TPV system.

[0082] In another embodiment of the TPV system described herein, an optical cavity is used for the TPV-based wireless power transmission system. The optical cavity may be in various forms of ellipsoids and / or geometric equivalents. The shape and size of the optical cavity may be adjusted to support, tune and / or match the range of applications.

[0083] Methodology - As noted above, an important aspect of a TPV system is to demonstrate the absorber / emitter can operate under high-temperature cyclic conditions for extended periods of time, longer than those reported in the literature to date. As well, two- and three-dimensional photonic crystals and metamaterials have been used as absorbers / emitters for TPV applications to spectrally tailor their emittance spectra, however, effective selective emitters made in the form of complex photonic structures with nano- or micro-scale periodicity have not yet demonstrated high-temperature and long-term stability. As an alternative to using two- and three- dimensional photonic crystals and metamaterials, planar structures can be used to fabricate selective emitters that can withstand high temperatures for prolonged periods of time. For example, planar emitters can be fabricated on tungsten substrates. Tungsten has an exceptionally high melting temperature of 3,422 °C and the lowest vapour pressure at temperatures above 1650 °C, and can thus provide a robust support for a TPV emitter.

[0084] Atmospheric attenuation can severely decrease transmitted beam power, especially over the electromagnetic wavelength range used in laser power transmission. Transferring the electromagnetic wave in the form of a periodically pulsed power beam may alleviate atmospheric attenuation. Using electromagnetic wavelengths for which the atmosphere is transparent, or has a low absorption coefficient, also mitigates atmospheric attenuation.

[0085] Along with the advantages of multi-source TPV systems, monolithic absorbers / emitters coated with optical films and designed to selectively capture specific wavelengths of laser sources and / or solar radiation incident onto a TPV system, bring more advantages to the system. For example, thermal cycling, chemical, thermomechanical, and high temperature stability. Furthermore, optical performance (in the form of spectral selectivity), and scalability of fabrication can be achieved. Figure 2, described below, shows the target area considered in this monolithic absorber / emitter TPV-based wireless power beaming.

[0086] Figure 2 is a Venn diagram of different criteria for achieving highly efficient, sustainable, and durable monolithic absorber / emitter TPV-based wireless power beaming. The three criteria are optical performance 202 (i.e., spectral, and / or directional selectivity), high temperature stability 204 (i.e., thermal cycling, chemical stability, thermomechanical stability), and large area fabrication 206 (i.e., scalability). The target area 208 for a functional monolithic absorber / emitter is an optimization of the three criteria.

[0087] For example, for monolithic structures with a tungsten substrate the following coatings are highly matched in thermal expansion coefficients: Ta, Ru, Re, Os, Nb, Mo, Ir, Hf, WSi2, MoSF2, ZrB2, TiB2, HfB2, LaB6, ZrC, VC, TiC, TaC, Ta2C, NbC, SiC, B4C, a-C, ZrN, VN, TiN, NbN, HfN, ScN, BN, AIN, ZrO2, YSZ, Ta2O5, HfO2, Cr2O3, Yb2O3, Y2O3, Sc2O3, l_u2O3, Gd2O3, Dy2O3, BeO, AI2O3, MgAI2O4. Other similar coatings may be used.

[0088] And the following materials are highly matched in phase equilibria for the tungsten substrate: Re, Os, Ir, Hf, WSi2, TaSi2, ZrB2, TiB2, LaB6, ZrC, VC, TiC, Ta2C, NbC, SiC, B4C, C, a- C, ZrN, VN, TiN, NbN, HfN, ScN, BN, AIN, ZrO2, YSZ, Ta2O5, HfO2, Cr2O3, Yb2O3, Y2O3, Sc2O3, LU2O3, l_a2O3, Gd2O3, Dy2O3, MgO, CaO, BeO, AI2O3, MgAI2O4. Other similar materials may be used.

[0089] The state-of-the-art for a monolithic absorber / emitter (1 D photonic crystal) includes: i) Experimental investigation on the long-term stability of selective emitters at high temperatures has shown that their performance degrades as sharp edges and features become rounded, and their composition changes due to phase changes and chemical degradation such as the formation of oxides [Sakakibara et al., 2019], The longest duration a selective emitter was tested for at temperatures above 1600 K was 12 hours, and this test was conducted on a Hf02-coated tungsten (W) inverse opal photonic crystal. SEM images revealed the photonic crystal structure was still intact after a 12-hour heat treatment at 1673 K, but underwent increased grain growth, cracking, and deformation [Arpin et al., 201 1], ii) The use of tungsten supports to fabricate emitters for solar TPV systems has been reported in the literature. Ungaro et. al. used laser texturing to modify the surfaces of a tungsten substrate to fabricate an absorber / emitter for a solar TPV system [Ungaro et al., 2015], A dielectric coating was deposited on the emitting surface to increase the emittance of radiation with wavelengths in the vicinity of 1400 nm, which have energy above the band gap of the GaSb PV cells used within the system. An overall power solar-to-electric power conversion efficiency of 6.2% was measured for this system. iii) Shimizu et. al. fabricated a planar spectrally selective absorber / emitter in the form of multilayer coatings comprised of thin tungsten films sandwiched between yttria- stabilized zirconia (YSZ) films [Shimizu et al. 2015], These films were deposited on a tungsten substrate. The thicknesses of the YSZ / W / YSZ films (from outside to inside) on the absorber side of the substrate was 20 nm / 15 nm / 200 nm, while that of the films for the emitter size was 20 nm / 15 nm / 400 nm. The optical performance of the multilayered absorber / emitter was of high quality, as the emitter exhibited high absorbance (and high emittance) for in-band photons and a low absorbance (and low emittance) for out-of-band photons. Further, the absorber exhibited high absorptance over the solar spectrum and a low emittance for longer wavelengths. A total system efficiency of 8% was obtained.iv) Dias et. al., 2023, proposed depositing thin films comprised of YSZ, MgO, CaO, HfN, or AIN films on tungsten substrates to provide mechanical stability and durability at high temperatures for long durations. By varying the thicknesses of the films at the top of the tungsten substrate a high absorptance will be achieved for incident light. Further, by tailoring the thicknesses of the films on the bottom of the tungsten substrate its emission spectra will be favorably matched with the spectral efficiency of an underlying PV cell.

[0090] In one embodiment, the TPV system uses a monolithic absorber / emitter to selectively capture specific wavelengths of laser sources and / or solar radiation incident onto the TPV system. The absorber is optimized to absorb radiation at the wavelength of the incoming wireless power beam, and the emitter is optimized to emit radiation at the wavelength matched with the bandgap (Eg) of the PV cell to convert it to electricity.

[0091] While monolithic absorber / emitters as a general concept are known in the art, they have not been used in TPV systems for wireless power transmission (WPT). The additional challenges and issues which arise for WPT necessitate alternative materials, configurations, and methods as described herein.

[0092] Figure 3 shows a wireless power beaming TPV system 300 with a PV cell 310, a tungsten absorber / emitter 320 and with multiple heat sources 330 and 340. In this example, the TPV-based wireless power transmission system is powered by combustion (system thruster 330) and a laser / electromagnetic wave 340 on the monolithic absorber.

[0093] The absorber / emitter 320 includes a sandwiched tungsten selective emitter and a sandwiched tungsten selective absorber.

[0094] The PV cell 310 is a GaSb PV cell.

[0095] Different combinations of multi / single-layer monolithic absorbers / emitters can be used to optimize the absorber to the incoming wavelength and maximize the in-band (useful) emission on the emitter side based on the type of the PV cell.

[0096] The TPV system 300 includes a first optical filter designed for wireless power transmission (WPT), a second optical filter to allow in-band photons to be transmitted to the PV cell, a vacuum port for infiltrating with an inert gas, and an active cooling system.

[0097] Three exemplary structures for the wireless power beaming TPV systems with monolithic absorber and emitter are shown in Figures 4, 5 and 6.

[0098] In Figure 4, a TPV system 400 is shown in which a power beam is in the form of a concentrated electromagnetic wave 440 as one of the heat sources is incident onto the robust tungsten-based single / multilayer absorber 422 which is thermally coupled to an emitter 424. Another heat source is transferred from a combustion chamber 430. The emitter 424 is a tungsten-based monolithic emitter with the emission matched with the bandgap of the PV cell 410 (GaSb PV cell in this case). A cooling system 450 is used to prevent the temperature of the PV cell 410 from elevating. The PV cell 410 could be passively cooled by attaching an origami-basedradiative cooling structure, as shown in Figure 4. The origami structure is composed of multilayers and multi-materials which are optimized and minimized based on its weight and volume to have the maximum cooling power for different space applications. In Figure 4, the origami structure radiative cooling includes an inner disc of a first material and an outer disc of a second material.

[0099] Figure 5 shows another example of the monolithic absorber 522 and emitter 524 TPV- based wireless power beaming system 500 powered by multiple sources such as incoming concentrated electromagnetic wave 540 and combustion 530. The TPV system comprises an ellipsoidal cavity 560 wherein thermal emission from the emitter 524 (which is located at one of the focal points of the ellipsoid) is directed to a low-band gap PV cell 510 (for example GaSb) which is located at the other focal point of the ellipsoid. The inner surface of the optical cavity is made up of a highly specular reflective coating in the IR region (For example Aluminum or Gold). A selective heat mirror matched with the incoming wavelength can be added on top of the opening of the ellipsoidal optical cavity 560 or the emitter 524 to further decrease the emission losses and increase the photon recycling.

[0100] The TPV system shown in Figure 6 is similar to that shown in Figure 5, with a PV cell 610, an absorber / emitter 620, a combustion heat source 630, and an ellipsoid optical cavity 660, but the ellipsoidal optical cavity 660 has a vacuum port 670. The vacuum port enables a vacuum to be generated within the cavity to decrease convection heat transfer and therefore decrease heat loss.

[0101] In Figure 7A, a power beam 740 in the form of a concentrated electromagnetic wave is incident onto an absorber / emitter 720. The absorber / emitter spans the foci area of an oblate hemispheroidal optical cavity 762 to maximize the photon recycling [Talebzadeh et al., 2021] and increase the temperature of the emitter to increase the system efficiency and output power density. A selective heat mirror 780 matched with the incoming wavelength can be added on top of the emitter 720 to decrease the emission losses and increase the photon recycling. Emission losses could also be decreased by using a monolithic spectrally selective absorber to absorb the incoming light while limiting the emitting limited amounts of emitted radiation with wavelengths or directions that cannot be converted to electric power in the PV cell 710.

[0102] The TPV system of Figure 7A also includes cooling fins 750 positioned nearthe PV cell 710 for reducing heat at the PV cell.

[0103] The TPV system shown in Figure 7B is similar to that shown in Figure 7A, but with the optical cavity in the shape of an oblate ellipsoid 764 instead of an oblate hemisphere. In this structure the absorber can also be a blackbody as the upward emission is reflected to the blackbody and recycled. A part of the top hemisphere is assumed to be a transparent selective surface that allows incident solar radiation or an electromagnetic power beam to pass while reflecting radiation emitted from the blackbody emitter / absorber.

[0104] Figure 7C shows the multisource-based TPV configuration for wireless power transmission (WPT). The TPV system can be heated with different heat inputs simultaneouslyand / or non-simultaneously. Examples of heat inputs shown in Figure 7C are waste heat and concentrated solar irradiance, but other heat sources are possible including multifuel combustion, etc.

[0105] The TPV configuration includes a storage block to store power for wireless power transmission.

[0106] The TPV configuration also include a system for waste heat recovery by a transfer heat fluid.

[0107] It should be noted that for all configurations and structures, it is possible to add an optical filter on top of the PV cell to further increase the photon recycling and system efficiency.

[0108] Figures 8-32 represent results of tests and experiments which illustrate the advantages of the monolithic selective absorber / emitter TPV systems with multi-heat sources for wireless power beaming / transfer.

[0109] Figures 8 shows a sample configuration for the absorber side of a monolithic absorber / emitter TPV system. Aluminum Nitride (AIN) with different thickness is coated on a tungsten (W) substrate. The graph 800 shows the effect of different AIN coating thicknesses (Onm, 10nm, 20nm, 60nm, and 100nm) on normal-direction spectral emissivity (secondary Y-axis). Figure 8 also shows the spectral solar emissive power as an example of one of the input heat sources (primary Y-axis). As shown in Figure 8, this structure has a high absorption in the range of solar irradiance.

[0110] Figure 9 shows the normal-direction total solar absorption of the absorber / emitter of Figure 8 as a function of the AIN thicknesses. The graph 900 shows that the maximum solar absorption of 75% is achieved for the AIN coating thickness of 60 nm.

[0111] Figure 10 shows another configuration of the monolithic absorber for the TPV system in which one of the heat sources is solar irradiance. In this structure an optimized thickness of 2.5 pm of ZrO2coating on the tungsten substrate results in 89% normal directed total solar absorption. The graph 1000 shows the direct+circumsolar irradiance and normal-direction spectral emission of the proposed structure. The structure is also suitable for the emitter section as the spectral emissivity is very high (close to 1) for in-band photons of a GaSb PV cell (Eg = 1 .72 urn) and very low emissivity for the out-of-band photons.

[0112] Figure 11 represents the emitter section of a TPV system, wherein the substrate is tungsten, and the coating is AIN. The plot 1100 shows the normalized blackbody spectral emissive power for three emitter temperatures of Temper = 1000 K, 1500 K, and 2000 K. The plot also shows the normal-direction spectral emittance for four cases when there is no coating (bare tungsten “Bare W”), and where the thickness of the AIN coating is 20, 40, or 60 nm. The dashed line splits the spectrum into in-band and out-of-band regions according to the bandgap of the GaSb PV cell (Eg = 1 .72 urn)

[0113] Figure 12 shows the results of the emitter section (AIN coating on tungsten substrate) based on three indicators for three emitter temperatures of Temitter = 1500, 1900, and 2300 K. Thefirst indicator (A) shows the rate of the total in-band (Eg = 1.7 pm) blackbody emissive power over the total blackbody emissive power, which represents, if the emitter is a blackbody emitter, what percentage of the emission is in-band (Eg > 1.7 pm). As expected, the higher the emitter temperature, the higher the in-band emission available for the GaSb PV cell to generate electronhole. The other indicator (B) shows what percentage of the emissive power of the proposed structure with different AIN coating thicknesses is in-band. As shown, For Temitter =1500 K, the AIN thickness of d = 100 nm on the tungsten substrate generates the maximum rate of in-band emissive power which is 67%. Similarly, when the emitter temperatures are Temitter = 1900 and 2300 K, the AIN thickness of 80 nm on the tungsten substrate generates the maximum rate of in- band emissive power which is 81% and 88%, respectively. The last indicator (C) shows the rate of the in-band emissive power of the proposed structure to the total-in-band blackbody emissive power. The results show that for all those three temperatures, 100 nm coating of AIN on the tungsten substrate provides the maximum in-band emission percentages of 64.5, 69, and 72% for Temitter = 1500, 1900, and 2300 K, respectively.

[0114] Only one of each indicator bar is labeled, however, in each group of three bars on the graph the left bar is A, the middle bar is B, and the right bar is C.

[0115] Figure 13 shows a novel configuration comprising an emitter with an air-bridge structure to minimize the thermal cycling, chemical, and thermomechanical stability challenges. The airbridge structure includes only one material with an airgap. As shown in this figure, the airgap is d = 200 nm and a tungsten film with different thicknesses (shown in nm on graph 1300) is located above the air-gap. Graph 1300 shows the structure has suitable spectral emissivity behavior for both solar irradiance absorption and high in-band emission on a GaSb PV cell.

[0116] Similar to Figure 13, in Figure 14 the thickness of the air-bridge is constant at d = 500 nm on graph 1400

[0117] Figure 15 is based on a SiO2 dielectric-bridge with three different thicknesses of d = 100, 300, and 500 nm while the thickness of the tungsten coating on the SiO2dielectric bridge is 10 nm for all cases, shown on graph 1500. The dashed line shows the bandgap of a GaSb PV cell.

[0118] Figure 16 shows another configuration referred to as a T-shaped emitter / absorber. In this structure a T-shaped tungsten structure is patterned and bonded on a tungsten substrate. The width and height of the pole of the T-shape is 100 nm and the thickness of the top of the T is 10 nm. The results (graph 1600) show that this structure has great potential for solar absorption and in-band emission. Line A represents absorptance, line B represents total reflectance, and line C represents total transmittance.

[0119] Figure 17 shows a monolithic absorber structure with an AIN coating with an optimized thickness of d = 4.5 pm on a tungsten substrate to capture a beam from a CO2laser which emits radiation with a wavelength of 10.6 pm. The results (graph 1700) show the maximum absorptionof 99.8% is achieved at a wavelength of 10.6 pm. Line A represents absorptance, line B represents total reflectance, and line C represents total transmittance.

[0120] Figure 18 shows the normalized blackbody emissive power for four blackbody emitter temperatures of T = 1000, 1500, 1800, and 2200 K, and the spectral absorptivity of the optimized monolithic structure for the CO2laser at A = 10.6 pm, on graph 1800. The emission of the structure is very low in a wide range of the spectral emissive power temperatures.

[0121] Figure 19 shows the rate of the total emissive power loss (emission loss toward topside) for the proposed AIN / W structure in Figure 17 as a function of the absorber temperature, on graph 1900. For example, the absorber optimized for a CO2 laser, has a minimum of 13.8% emission loss at Twitter = 1000 K and 23% loss for Temitter = 1800 k.

[0122] Figure 20 shows, on graph 2000, that by adding a thin layer of gold (d = 100nm) between the W substrate and AIN coating, it is possible to further decrease the emission loss from the absorber. Figure 20 shows the absorptance (A), reflectance (B), and transmission (C) of the W / Au / AIN sandwiched structure.

[0123] Figure 21 shows the rate of total emissive power (emission loss toward topside) for the proposed structure of Figure 20 with a 100 nm of gold coating between AIN and W as a function of the emitter temperature, on graph 2100. For example, the absorber optimized for a CO2 laser has a minimum of 4.36% emission loss at Temitter = 2100 K. (It should be noted that the melting temperature of Gold is TAu-meit = 1340 K and other coatings can be used as needed depending on the operating temperature).

[0124] Figure 22 shows a design of a monolithic absorber / emitter that exhibits different absorption peaks. The absorber could be used to receive two incoming monochromatic laser beams with peak wavelengths of 10.6 pm (e.g. from a CO2laser) and ~300 nm (e.g. from a Xenon Chloride laser, which has a smaller beam divergence angle). A bare substrate of AIN provides a very high spectral emissivity at ~300 nm and 10.6 pm and very low spectral emissivity (emission loss) in the range of ~ 400 nm to 10 pm, as shown on graph 2200. Line A represents absorptance, line B represents total reflectance, and line C represents total transmittance.

[0125] Figure 23A shows the total spectral emissive power (spectral emission loss toward upside of the absorber) for the AIN substrate for four different emitter temperatures of Temitter = 1000, 1500, 2000, and 2500 K, on graph 2300a. Figure 23B shows the rate of the total emission loss as a function of Temitter, on graph 2300b. As shown, the AIN substrate has a minimum loss of 0.85 % at Temitter=2360 K.

[0126] Figures 24 to 32 show experimental / simulation results for radiative origami cooling structures used under the PV cell such as 450 ad 550 shown in Figures 4 and 5.

[0127] Figure 24 shows, on graph 2400, the simulation results for a 30cm x 30 cm square plate when the applied heat / power on the PV cell is 33.5 W / cm2(3500 Sun x 1366 W / m2space solar irradiance x 0.7 converted to heat on the PV cell). Figure 24 shows the cell temperature as a function of the thickness of the copper radiative cooling plate.

[0128] Figure 25 shows the impact of varying cross-sectional areas on cell temperature, on graph 2500. In Figure 25, the volume of the Cu cooling plate is constant at 90 cm3with a square cross section.

[0129] Figure 26 shows, on graph 2600, the simulation results of the effects of varying the cooling plate composition by keeping the volume constant but changing the material in the planar direction. The cross sections of the configurations are: A) C-AI-Cu, B) Cu-AI-C, C) C-C-C, D) Cu- Cu-Cu, E) AI-AI-AI, and F) Cu-C-AI. Figure 26 shows the temperature distribution from the center of the structure where the PV cell is located up to the outer edge of the structure for different cooling pate composition arrangements. The cooling plate is circular.

[0130] Figure 27 shows, on graph 2700, the simulation results on the effect of varying the cooling plate geometry by keeping the volume constant but changing the material in the planar and vertical directions. In space applications, it is important to minimize the weight and volume of the components. The configurations are A) Cu-AI-C (vertical), B) Cu-AI-C (horizontal), C) Al, and D) Cu only. Figure 27 shows the temperature distribution from the center of the structure where PV cell is located up to the outer edge of the structure for different horizontal and vertical arrangements of the cooling plate. The cooling plate is circular.

[0131] Figure 28A shows the experimental design of the radiative cooling plate. It is a square plate with dimensions of 24 cm x 24 cm x 0.5 mm. The material is varied horizontally. The inner plate is copper, and the outer plate is aluminum. A ceramic emitter was used with 10 W of power applied. A 12 cm x 12 cm inner square cutout is used for multi-material section with trapezoidal cutouts used for the external part. The sections were joined by highly conductive thermal graphite.

[0132] Figure 28B shows the experimental results with the configuration arrangements of A) Al-Cu, B) Cu only, C) Al only, and D) Cu-AI. Figure 28B shows the temperature gradient across the structure measured by six thermocouples located consequently / in sequence.

[0133] Figure 29 shows, on graph 2900, simulation results attained using Comsol Multiphysics™ software for the radiative cooling structure. The dimensions of the structure are similar to that of the structure shown in Figure 28A. Real conductance between different materials in the experimental setup is unknown due to uneven contacts between the material interfaces. A range of conductance values are considered in the simulation and shown in the inset. The lines for copper are top to bottom from 3-138, and the lines for aluminum are the opposite, from bottom to top from 3-138. There exists a temperature difference between the bottom of the emitter and the center of the structure due to thermal resistance. In this configuration the outer plate is Cu and inner plate is Al, and the power is 4 W. Figure 29 shows the temperature as a function of the plate arc-length from the center to the edge with different thermal conduction coefficient (hc).

[0134] Figure 30 is similar to Figure 29 with the input power of 5 W (shown on graph 3000). As with Figure 29 a range of conductance values are considered in the simulation and shown in the inset. The lines for copper are top to bottom from 4-139, and the lines for aluminum are the opposite, from bottom to top from 4-139.

[0135] Figure 31 is similar to Figure 29 with changed material arrangements. Al is the outer plate and Cu is the inner plate. The lines of graph 3100 are opposite to Figures 29 and 30, with the lines for copper arranged bottom to top from 3-138, and the lines for aluminum from top to bottom from 3-138.

[0136] Figure 32 is similar to Figure 29 with changed material arrangements and input power. Al is the outer plate and Cu is the inner plate. The input power is 5 W. The lines, on graph 3200, for copper are arranged bottom to top from 4-139, and the lines for aluminum from top to bottom from 4-139.

[0137] Figures 33 through 36 show further results involving the use of different material configurations, namely horizontal, vertical, and diagonal configurations, to compare and determine the best choice for multi-material radiative cooling.

[0138] Figure 33 shows a cross-section of a cooling plate with 3 different sections in the horizontal direction. A material sweep was conducted with these 3 sections with the material orders varied. It can be observed from Figure 33 that there are 3 distinct temperature range clusters recorded at the middle of the radiative cooling plate (on graph 3300). The temperature range between 331 K and 337 K shows the results using copper in the middle, the temperature range between 365 K and 372 K corresponds to aluminum in the middle while the temperature range between 381 K and 387 K represents carbon-fibre composite in the middle. The results show that having a material with the highest thermal conductivity at the center where the heat source is located provides the best thermal performance, as expected as the highest thermal conductivity allows for the most heat to dissipate away from the heat source in the shortest amount of time.

[0139] Figure 34 provides a comparison of the temperatures at the center of the cooling plate taken from the results shown in Figure 32. Figure 34 shows, on graph 3400, that the cooling plate made of all copper panels provides the best cooling performance while the one made from all carbon fibre is the worst. Carbon fibre has the lowest thermal conductivity of the three and this explains its performance. The copper-aluminum-carbon fibre ordered cooling plate leads to a cell temperature only 3 K higher that the copper cooling plate and is the best performing case involving all 3 materials. The results indicate that using panels with decreasing conductivities as we move away from the center can cause only a small reduction in cooling performance while allowing for a reduction in cooling plate weight.

[0140] In order to examine the impact of using a sandwich structure with multiple material layers, further simulations were carried out. The simulation set involved the use of a vertical cross section, as shown in Figure 35, using the combinations of the same three materials. In Figure 35, it can be observed, on graph 3500, that the temperature profiles overlap each other. For the cases wherein the top layer was made with copper, the temperature at the center of the cooling plate ranged from 331 K to 359 K. When the top layer was aluminum and carbon the temperature at the center of the radiative cooling plate ranged from 341 K to 380 K and from 343 K to 387 K,respectively. These results further confirm that having copper directly in contact with the cell would result in the best cooling performance. However, there is a larger variation in temperature compared to the horizontal case.

[0141] Figure 36 shows a further breakdown of the results for all cases. Figure 36 shows, on graph 3600, that the presence of copper at the top layer or middle layer produces the best results except for the cases where carbon-fibre is present in the top or middle layers. The best case where all three materials are used, Cu-AI-C, resulted in a temperature of 354 K at the center which is a 23 K increase compared to the all copper best case. This is significantly higher than the 3 K increase shown in the horizontal case.

[0142] Two configurations of the proposed receiver architecture for the monolithic multilayer absorber / emitter-based TPV WPT are shown in figures 37 and 38.

[0143] Figure 37 a), b), and c) show various views / aspects of a stationary configuration of the multilayer absorber / emitter-based TPV WPT, for example mounted on ground. The absorber / emitter receives heat input as laser beams. The absorber / emitter has a spectrally selective coating on glass and a side reflector. The absorber / emitter is supported by a housing with a tilting and / or rotating mechanism and a support rod, mounted on a base. The absorber / emitter sits above a PV cell array within a vacuum created with a vacuum pump. The TPV includes a back reflector for photon recycling and liquid cooling pipes to prevent overheating of the PV cell array. The absorber / emitter is a sandwiched multi-layered monolithic spectrally selective absorber / emitter, comprising a tungsten / graphite substrate between the absorber and emitter sides.

[0144] Figure 38 at A shows a mobile configuration wherein the TPV WPT system in mounted on a drone. Figure 38 at B shows a mountable TPV WPT configuration example.

[0145] Figure 39 shows the spectral absorptance of the single-layer materials (noted on the left side) with melting temperatures of >2000 K and different thicknesses. The results shown in Figure 39 represent the spectral behavior of a single material and enable selection of a specific laser type for the material.

[0146] Figure 40 shows the normal spectral absorptance as a function of AIN thickness on W substrate (the substrate described in various configurations in Figures 7-23B). The red line shows the optimal thickness over spectral range of 300 to 12,000 nm for maximum absorption. This line is useful in using lasers with different wavelengths.

[0147] In some implementations, fuels may include: a) Fossil Fuels: Coal, Crude oil (Petroleum), Natural gas b) Renewable Fuels: Biomass (wood, agricultural residues, biofuels), Biodiesel, Ethanol, Hydrogen (often considered a fuel, especially in fuel cells), Methanol, Bioethanol c) Nuclear Fuels: Uranium, Thorium, Hydrogen or Helium fusiond) Synthetic Fuels: Synthetic diesel, Synthetic gasoline, Synthetic natural gas e) Alternative Fuels: Propane, Butane, Compressed natural gas (CNG), Liquefied natural gas (LNG) f) Metallic fuels: micro-thermites, nano-thermites, metals, metal alloys g) Space Resources: space debris (satellites, rocket bodies, space systems), Lunar regolith, Martian regolith, materials from asteroids and / or materials harvested from other celestial bodies.

[0148] In other implementations, the TPV system may be integrated with high heat applications such as metallurgy and foundry operations, glass manufacturing, ceramics products, chemical processes in industries such as petrochemicals, pharmaceuticals, and specialty chemicals, power generation systems, incineration and waste management, aerospace and automotive industries, semiconductor manufacturing, food processing, and or other experimental set high temperature reactions or material testing.

[0149] In other implementations, the TPV system may combine propulsion and power generation cycles.

[0150] In other implementations, the emitter may be a solid, liquid, gas, plasma, and / or Bose- Einstein condensates, and / or other state of matter or a combination thereof.

[0151] In other implementations, systems and methods are used for communication receivers and transmitters. Receivers may include one or more of the follow: traditional antenna, laser communication, atomic electrometry (e.g. Rydberg atoms), or the like, and or a combination of thereof. Transmitters, use radiative and non-radiative methods for power transmission. Atomic electrometry and or the like may be used in some implementations. In other implementations, wireless power transmission may be used.

[0152] In other implementations, methods incorporate to include analog and digital electromagnetic signals, detection, and imaging applications, and may use cold and / or hot Rydberg atoms. Other methods include using mixers, such as atomic mixer to enhance the target signal.

[0153] In other implementations, TPV systems and methods are used for application on Earth.

[0154] In other implementations, TPV systems and methods are used for applications in Space.

[0155] In other implementations, various fuels can be used to provide heat for the conversion. In other examples, metallic fuels can be used, which may include: metals, metal alloys, micro and / or nano energetic particles. In other examples, recyclable fuels may be used.

[0156] In other implementations, TPV systems may be incorporated and / or coupled with one or more other power / heat generating systems and methods to generate electricity.

[0157] In other implementations, fuels may be heated and / or undergo combustion.

[0158] In other implementations, TPV systems may be used to power a mobile / fixed system operating in / on Land, Air, Water, and / or Space.

[0159] In other implementations, a plurality of power distribution networks and topology methods may be used to share power in between and among a plurality of mobile systems.

[0160] In other implementations, semi-autonomous and / or autonomous systems and methods may be incorporated. Remote operations may be enabled using TPV systems.

[0161] In other implementations, systems and methods may be deployed in a plurality of smart cities and / or infrastructure to generate and transfer electricity.

[0162] In other implementations, a plurality of reflectors may be used.

[0163] In other implementations, a source used to power the TPV system may be an incident electromagnetic beam from a laser.

[0164] In other implementation the PV may be in different shapes and configurations, including regular polygons, to optimize recovery of correct band gap photons within the structure of the system.

[0165] In other implementations, a source used to power the TPV system may be an incident electromagnetic beam from a maser (MASER is the acronym for microwave amplification by stimulated emission of radiation).

[0166] In other implementations, microwave collimators including Cassegrain- , Horn- , Lens- , Dielectric Lens- , and Reflective Lens antennas, may be used to transmit and focus an electromagnetic beam to the TPV system to be used as a power source.

[0167] In other implementations a negative-index-of-refraction lens may be used to collimate an electromagnetic beam incident onto the TPV system.

[0168] In other implementations, a microwave concentrator, including planar and hyperbolic lenses, may be used to focus incident microwaves onto the TPV system.

[0169] In other implementations, metamaterials may be used to collimate and / or concentrate an electromagnetic beam incident onto the TPV system.

[0170] In other implementations, the power beam may be delivered as an electromagnetic pulse or as a periodically pulsed electromagnetic beam.

[0171] In other implementations, TPV systems and methods may be used to augment operations.

[0172] In other implementations, TPV systems and methods may be used on satellites and rovers.

[0173] In other implementations, TPV systems and methods may be used for power generation, and / or solar / natural gas power system as an output.

[0174] In other implementations, TPV systems may be integrated into central receiver concentrator, linear, and / or parabolic dish concentrators and / or other types of concentrators.

[0175] In other implementations, micro-channels and mesh-channel chemical process receivers are used.

[0176] In other implementations, TPV systems and methods may include filters, such as optical filters. Filters may be composed of layers of nanoparticles and / or microparticles. Layerswithin the filter may be a plurality of shapes and compositions to optimize TPV systems and methods.

[0177] In other implementations, filters used in TPV systems and methods may be additively manufactured.

[0178] In other implementations, advanced combined cycle power systems are used, and or in co-generation or multi-generation purposes.

[0179] In other implementations, the TPV system may be used to heat or sinter materials on Earth and / or space.

[0180] In other implementations, the TPV system may be used in solar chemical I solar thermochemical processes to help drive reactions.

[0181] In other implementations, the TPV system may be used to produce fuel, and / or preheat fuel.

[0182] In other implementations, possible applications include the combustion of the product syngas in a hybrid, solar / natural gas power plant, providing an efficient solar augment to the natural gas fuel; the thermochemical storage of solar energy, as part of an open or closed-cycle storage process; combined cycles; the production of hydrogen or the like for use in fuel cells and for other purposes; and the production of synthetic fuels such as methanol or long-chain hydrocarbons; materials for storage systems; storage systems.

[0183] In other implementations, the TPV system may be used for on-demand energy production and / or catalyst driven applications.

[0184] In other implementations, systems and methods may use Fresnel lens for the receiver and transmitter.

[0185] In other implementations, systems and methods are used for de-orbiting satellite systems.

[0186] In other implementations, the multi-source TPV can used to recharge a fleet of systems to increase operations and performance in harsh environments where sunlight is limited or not available. For example, multi-source TPV systems are equipped onto multi-layered constellation, and the constellation is recharged using a plurality of transmitters and receivers to generate power and / or propulsion. In other implementations, a plurality of transmitters may be used.

[0187] In other implementations, TPV systems can be attached to space debris, to power generation and distribution, and propulsion and / or debris removal purposes.

[0188] In other implementations, TPV systems may be incorporated into other byproducts and / or multi-fuel generation applications to create fuels such as metallic fuels, metals, alloys, nano and micro composites, additives hydrogen, ammonia, syngas or the like.

[0189] In other implementations, TPV systems may be used in in-situ resource utilization.

[0190] In other implementations, TPV systems to integrate with systems and methods at least one of: instruments and machines, components, systems in heavy industries, mining applications, consumer products and services, in space applications, isru on Moon, Mars, asteroids, or othercelestial bodies, in space habitats and other space architecture, in space analogues, remote locations, and other extreme environments.

[0191] In other implementations, TPV systems may be integrated into heat engines.

[0192] In other implementations, TPV systems may be for mobile vehicles operating on Land, Air, Water, and Space, including but not limited to drones, airships, submarines, aircraft, watercraft, spacecraft, space systems, space architecture or the like.

[0193] In other implementations, TPV systems and methods may be fixed or mobile.

[0194] In other implementations, TPV systems and methods may be used in combined power and propulsion cycles.

[0195] In other implementations, TPV systems and methods may be used in cogeneration, trigeneration, distributed and or other multigeneration systems or the like, and / or methods for heating and cooling.

[0196] In other implementations, TPV systems and methods for multigeneration system and / or other multi-source integrated energy system.

[0197] In other implementations, origami systems and methods may be used to implement TPV systems.

[0198] In other implementations, TPV systems may be used for thermal energy storage and / or in smart cities.

[0199] In an implementation, the use of a laser creates the conditions in an atmosphere for a conductor type column, which allows for optimal energy transfer from a co-linear electromagnetic beam. Various distribution methods between the 2 sources of energy transmitted from point to point, to a plurality of nodes. In other examples, a maser or other electromagnetic source may be used to create the initial conditions, to enable another source of electromagnetic radiation to be co-transmitted. Power distribution P2P to a plurality of receiving nodes may be transferred using a plurality of transmitters.

[0200] In other implementations, other geometric shapes may be considered such as polyhedrons (tetrahedron, cube, octahedron, dodecahedron, and / or icosahedron) or the like for the emitter, receiver, filters, and or optical cavity.

[0201] In other implementations, space resources may be utilized to additively manufacture the TPV system.

[0202] In other implementations, TPV system may incorporate waveguides.

[0203] In other implementations, TPV system may include Fresnel lens to focus the beamed power or transmitted band gap optimized photons.

[0204] In other implementations, one of the sources used to power a TPV system may be inductive-couple and / or magnetically coupled systems using primary and secondary coils to vary the magnetic fields to drive heating, sintering and combustion processes and / or application In other implementations, the multi-source TPV may be used as a processing, furnace and / or recycling system to receive materials, for heating materials to high temperatures throughcontrolled thermal processes to create useful byproducts. The multisource TPV system may be configured with a combustion chamber, where materials may be heated to drive reactions and / or heat materials to a high temperature, the byproducts are then directed to a set of compartments in which different materials could be stored. For recycling applications, materials to be recycled may be directed to the combustion chamber coupled with the multisource TPV system for heating purposes, where materials are heated and processed, after which byproducts are directed to a set of compartments for storage. Also, reflectors may be used to concentrate the solar energy to heat the combustion chamber, and / or directed energy may be used to increase the heat generation, and the TPV system is used to ensure a constant temperature is maintained in the combustion chamber. In other implementations, the combustion chamber coupled with TPV system may be used to recycle space debris or process space resources for space applications.

[0205] In other implementations, byproducts from the recycling of materials using the multisource TPV may be used as feedstock for fuel production and / or to support applications for in-orbit servicing, assembly, and manufacturing.

[0206] In other implementations, a cooling system may be integrated with the multi-source TPV for thermal control. Furthermore cooling systems may include one or more of the following: vapor-compression cycles through cycles of evaporation and condensation, evaporative cooling (e.g. evaporation of water to absorb the heat, cooling the air), radiative cooling, heat sinks, heat pipe or loop heat pipes using phase change and capillary action to transport heat away from sensitive components, fluid loops to circulate coolant fluids through heat exchangers and radiators, thermoelectric coolers such as Peltier devices, multi-layer insulation where layer of reflective materials are separated by spacers to reduce heat transfer, and / or phase change materials where excess heat is absorbed to change a phase change (e.g. solid to liquid) or the like.

[0207] In other implementations, the multi-source TPV system may be used as furnace for example, to operate as a blast furnace, electric arc furnace, induction furnace, reverberatory furnace, cupola furnace, solar furnace, combustion furnace, rotary kiln, and / or electric resistance furnace or the like.

[0208] In other implementations, the power generated using TPV may be distributed to receivers on Earth and in Space.

[0209] In other implementations, the power generated using TPV to power a plurality of network of systems on Land, Air, Water and Space.

[0210] In other implementations, one or more reflectors may be used to concentrate sunlight to the TPV to generate electricity. Furthermore, the electricity generated may be distributed to other receivers.

[0211] In other implementations, TPV system may be integrated in a high heat application in space, for example an incinerator in space to dispose of materials.

[0212] In other implementations, the TPV system may be integrated to a reaction chamber, to siphon waste heat and convert it to electricity. In other implementations the TPV ellipsoid system can be used with a scintillation filter to harvest optimized band gap photons from the gamma radiation produced in a fusion reaction. The container for the fusion reaction would be lined with reflective material such as tungsten and the PV receiver would be at a sufficient distance and actively cooled in an energy exchange system.

[0213] In other implementations the TPV ellipsoid system can be used to harvest as well as deflect to some extent the energy from a power beam weapon directed at a device or person and convert it into power for defense or active response.

[0214] In other implementations the TPV ellipsoid could be an inflatable, rigid or semi-rigid airship where the beamed power it receives is used for operation of it and its systems and any waste heat can be used for maintaining altitude buoyancy as well as propulsion.

[0215] In other implementations the TPV ellipsoid could be a clear, internally reflective system with cooled regular polygon receivers at each foci allowing for energy harvesting at any angle of solar incidence. This system could also be an airship with the same configuration intended to be utilized at altitude above the cloud cover, including in space, and able to use power beam technology to send power to a receiver on the ground, in the air or in space.

[0216] In other implementations, TPV systems may be used as transceivers. Fixed and / or Mobile systems and vehicles may be integrated with a plurality of transceivers (transmitter / receiver) for power and communication applications.

[0217] In other implementations, TPV systems transceivers may be used to power robots and or robotic systems on Earth and in Space. Robots and / or robotic systems include but are not limited to semi-autonomous robots, autonomous robots, exoskeletons, humanoids, a plurality of swarm robots, industrial robots and or service robots (indoor and outdoor for Earth Applications, surface and / or subsurface, and or orbital robotic systems.

[0218] In other implementations, TPV systems may power robotic systems to assemble, dismantle, and / or maintenance applications on Earth and in Space.

[0219] In one implementation, the TPV system is deployed on a satellite or orbital platform, wherein beamed electromagnetic radiation — such as laser, maser, mm-wave or microwave energy — is transmitted from a ground station or another satellite. The monolithic absorber / emitter structure is configured to selectively absorb incoming radiation and re-emit energy at wavelengths matched to the bandgap of photovoltaic cells disposed within an integrated optical cavity. The optical cavity may include reflective or photonic structures to further enhance photon recycling and emission control. Radiative cooling elements configured using origami-based geometries are deployed to passively manage thermal load in the vacuum of space.

[0220] In one implementation, the TPV system may also be utilized in industrial settings, wherein it captures and converts high-temperature waste heat from combustion systems, furnaces, or gas turbines. The monolithic absorber / emitter structures are optimized for high-temperature operation (>1200°C) and can be retrofitted into exhaust streams to absorb thermal radiation and convert it to electric power. Spectral selectivity of the thin film stack ensures efficient photon conversion and minimal heat loss to non-contributing wavelengths.

[0221] In another embodiment, the TPV system is configured for portable or remote energy generation applications, including field operations, disaster relief, or off-grid infrastructure. A compact wireless power source (e.g., a laser or microwave emitter) transmits energy to a portable TPV receiver unit incorporating the absorber / emitter structure. The system's lightweight, foldable radiative cooling array allows for efficient thermal management without active cooling systems, making it suitable for rugged or austere environments.

[0222] In one implementation, the TPV system is integrated into an unmanned aerial vehicle (UAV) to enable mid-flight wireless power transfer. Directed electromagnetic radiation, such as laser beams transmitted from a ground station or companion drone, is absorbed by the onboard monolithic absorber / emitter structure. The re-emitted spectrally controlled radiation is converted into electrical power by integrated photovoltaic cells. The system extends flight duration and mission capability without requiring physical refueling or landing.

[0223] In another embodiment, the TPV system is adapted for wireless power delivery in subsurface or underwater environments. In such settings, traditional electrical cabling is impractical due to corrosion, complexity, or mobility needs. Electromagnetic radiation (e.g., microwave, maser, UV or near-infrared) is transmitted from a surface station to a submerged receiver. The monolithic absorber / emitter structure is optimized for minimal scattering and high spectral selectivity in water-permissive frequency ranges such as UV spectrum. Radiative cooling elements help manage thermal load within pressurized or thermally insulated enclosures.

[0224] In another embodiment, in a space exploration applications, the TPV system is deployed as a wireless receiver module on the surface of the Moon, Mars, or other extraterrestrial bodies. A central solar power array or orbital station beams energy to multiple distributed TPV receiver units for powering habitats, rovers, or instrumentation. The monolithic absorber / emitter structures operate reliably in extreme thermal cycles and vacuum conditions. Foldable or origamistyle radiators are used to enhance passive cooling where convection is not available.

[0225] In another embodiment, in a space exploration applications, the TPV system may receive thermal energy may be received or collected from natural heat sources located on or near extraterrestrial bodies, including the Moon, Mars, asteroids, or other planetary or non-planetary celestial entities.

[0226] In some implementations, the TPV system may be miniaturized and integrated into wireless, battery-free sensors deployed in remote or hazardous environments. Energy is transmitted via laser or microwave from a central node and converted to electrical power for local sensing and communication functions. The high durability and compactness of the monolithic absorber / emitter structure enable long-duration operation without maintenance.

[0227] In one embodiment, the TPV system is installed on an electric vehicle (EV) and used to receive wireless power from roadside or overhead transmitters, enabling in-motion charging. The system’s absorber / emitter structure is thermally and spectrally optimized for rapid energy conversion, and radiative cooling panels are integrated into the vehicle body to passively manage waste heat.

[0228] In some implementations, the TPV system may be used in conjunction with a thermal battery to receive pulsed or intermittent high-energy radiation, store the thermal energy in a heatretaining medium, and gradually convert it into electrical power via the absorber / emitter and PV cell system. This is useful for applications where continuous transmission is impractical (e.g., military, space missions, or stealth operations).

[0229] In another use case, TPV systems are used for secure, air-gapped wireless power transmission in high-security environments. Directed electromagnetic radiation is confined within a controlled line-of-sight path to prevent interception. The absorber / emitter structures are optimized to match the spectral output of the transmitter and the bandgap of the photovoltaic receiver to maximize conversion efficiency while minimizing unintended emissions.

[0230] In this implementation, TPV receiver modules are mounted on autonomous robots, drones, or actuators inside industrial or cleanroom environments. Instead of wired power or inductive pads, overhead laser transmitters deliver energy to the mobile devices via line-of-sight. The monolithic emitter's thermal and spectral properties are tuned for maximum conversion and reliability under constant cycling.

[0231] While the above description provides examples of one or more apparatus, methods, or systems, it will be appreciated that other apparatus, methods, or systems may be within the scope of the claims as interpreted by one of skill in the art.

Claims

Claims:1 . A thermophotovoltaic (TPV) system comprising: a monolithic-absorber and emitter configured to selectively capture specific wavelengths of laser sources, solar radiation, and / or any electromagnetic and acoustic wave; at least one photovoltaic (PV) cell; wherein the absorber is optimized to absorb radiation at a wavelength of an incoming wireless power beam; and wherein the emitter is optimized to emit radiation at a wavelength matched with a bandgap of the PV cell to convert thermal emission heat to electricity.

2. The TPV system of claim 1 , wherein the monolithic absorber and emitter comprises: planar multilayered structures fabricated on different substrates; and thin films with different thicknesses are deposited onto the substrate to form a spectrally selective and durable absorber and emitter.

3. The TPV system of claim 2, wherein the thin films are selected from materials durable in high temperatures, including at least on of: Ta, Ru, Re, Os, Nb, Mo, Ir, Hf, WSi2, M0SF2, ZrB2, TiB2, HfB2, LaB6, ZrC, VC, TiC, TaC, Ta2C, NbC, SiC, B4C, a-C, ZrN, VN, TiN, NbN, HfN, ScN, BN, AIN, ZrO2, YSZ, Ta2O5, HfO2, Cr2O3, Yb2O3, Y2O3, Sc2O3, l_u2O3, Gd2O3, Dy3O3, BeO, AI3O3, MgAhOzi.

4. The TPV system of claim 1 , further comprising: an optical cavity in various forms of ellipsoids or geometric equivalents, wherein the optical cavity is configured to support, tune, and / or match the range of applications .

5. The TPV system of claim 4, wherein the optical cavity comprises: an ellipsoidal cavity with the absorber / emitter spanning the foci area; and a highly specular reflective coating on the inner surface in the infrared (IR) region.

6. The TPV system of claim 1 , wherein the absorber / emitter is designed to receive radiation from multiple sources including: laser power beaming, microwave or RF power beaming, electromagnetic power delivered through optic cables, concentrated solar radiation, solar irradiance, fuels, waste heat, and nuclear energy sources.

7. The TPV system of claim 1 , wherein the absorber and emitter operates under high- temperature cyclic conditions for extended periods of time.

8. The TPV system of claim 1 , wherein the PV cell is passively cooled by an origami-based radiative cooling structure.

9. The TPV system of claim 1 , wherein the system is configured for wireless power transmission (WPT).

10. The TPV system of claim 1 further comprising a radiative cooling structure positioned under the PV cell.11 . The TPV system of claim 10 wherein the radiative cooling structure further comprises: a square cooling multi-material plate with dimensions of 24 cm x 24 cm x 0.5 mm, wherein the cooling plate material varies horizontally with an inner surface of copper / aluminum and an outer surface of aluminum / copper, joined by highly conductive thermal graphite.

12. The TPV system of claim 10 wherein the cooling plate geometry is varied by changing the material along a first direction while maintaining a constant volume in order to enhance thermal dissipation, wherein the first direction is one of horizontal, vertical, and planar.

13. The TPV system of claim 10 wherein the cooling plate geometry varies by changing the material in both a first direction and a second direction to optimize the temperature distribution and heat dissipation across the structure.

14. The monolithic absorber and emitter TPV of claim 1 further comprising an optical filter on top of the PV cell.

15. A method of forming a multilayered monolithic absorber and emitter for use in a TPV system, the method comprising: depositing at least one layer of a coating onto a monolithic substrate which is configured to absorb photons and emit heat, wherein the coating determines a spectral selectivity and a durability of the absorber and emitter.

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