The spectral control is widely incorporated with the thermophotovoltaic (TPV) technology to improve the optical-electric conversion efficiency of the whole sys- tem. In order to match with GaSb photovoltaic cell, an 8...The spectral control is widely incorporated with the thermophotovoltaic (TPV) technology to improve the optical-electric conversion efficiency of the whole sys- tem. In order to match with GaSb photovoltaic cell, an 8-layer one-dimensional photonic crystals (PC) filter structure was designed as quarter-wave periodic structure by selecting silicon (Si) and silicon dioxide (SiO2) as candidate materials. The multilayer Si/SiO2 structure was developed for the matching filter to simulta- neously realize the optimal matching with the spectral distribution of the high temperature emitter and the quantum efficiency of GaSb cell. The physical vapor deposition (PVD) method was used to fabricate the optical filter and the normal incidence optical property of the filter was measured within the spectral range from 0.7 to 3.3 μm. These experimental data were used to predict the spectral control performance in a TPV system. Finally, temperature performance experiments were carried out to establish its withstanding performance in high temperature envi- ronment.展开更多
Near-field thermophotovoltaic(NTPV)devices comprising a SiC-hBN-graphene emitter and a graphene-InSb cell with gratings are designed to enhance the performance of the NTPV systems.Fluctuational electrodynamics and rig...Near-field thermophotovoltaic(NTPV)devices comprising a SiC-hBN-graphene emitter and a graphene-InSb cell with gratings are designed to enhance the performance of the NTPV systems.Fluctuational electrodynamics and rigorous coupled-wave analysis are employed to calculate radiative heat transfer fluxes.It is found that the NTPV systems with two graphene ribbons perform better due to the graphene strong coupling effects.The effects of graphene chemical potential are discussed.It is demonstrated that near-field radiative heat transfer of thermophotovoltaic devices is enhanced by the coupling of surface plasmon polaritons,surface phonon polaritons,hyperbolic phonon polaritons,and magnetic polaritons caused by the graphene strong coupling effects.Rabi splitting frequency of different polaritons is calculated to quantify the mutual interaction of graphene strong coupling effects.Finally,the effects of cell grating filling ratio are investigated.The excitation of magnetic polaritons is affected by the graphene ribbon and the cell filling ratio.This investigation provides a new explanation of the enhancement mechanism of graphene-assisted thermophotovoltaic systems and a novel approach for improving the output power of the near-field thermophotovoltaic system.展开更多
The near-field effect can be used to improve the output power of the near-field thermophotovoltaic device(NTPV).The nearfield radiative heat transfer in the near-field thermophotovoltaic device can be enhanced by the ...The near-field effect can be used to improve the output power of the near-field thermophotovoltaic device(NTPV).The nearfield radiative heat transfer in the near-field thermophotovoltaic device can be enhanced by the excitation of hyperbolic modes and the coupling of surface plasmon polaritons.In this study,we design a two-body near-field thermophotovoltaic system based on hyperbolic metamaterial.The multilayer structure on the emitter is composed of Ga-doped ZnO(GZO)and hafnium dioxide(HfO2).The gratings are on the InAs photovoltaic cell.Fluctuational electrodynamics and rigorous coupled-wave method are employed to calculate radiative heat transfer.It is found that the NTPV system with multiple microstructures performs better than the NTPV system just with single micro-structures.This NTPV system performs better in a wider vacuum gap.The output power and efficiency are enhanced by the GZO-HfO2surface plasmon polaritons in multilayer structure.The gratings can monitor the spectral heat flux to match the cell band gap to enhance the performance of the near-field thermophotovoltaic system.This investigation provides a novel approach for improving the output power of a two-body near-field thermophotovoltaic system.展开更多
Micro/nanostructures play a key role in tuning the radiative properties of materials and have been applied to high-temperature energy conversion systems for improved performance.Among the various radiative properties,...Micro/nanostructures play a key role in tuning the radiative properties of materials and have been applied to high-temperature energy conversion systems for improved performance.Among the various radiative properties,spectral emittance is of integral importance for the design and analysis of materials that function as radiative absorbers or emitters.This paper presents an overview of the spectral emittance measurement techniques using both the direct and indirect methods.Besides,several micro/nanostructures are also introduced,and a special emphasis is placed on the emissometers developed for characterizing engineered micro/nanostructures in high-temperature applications(e.g.,solar energy conversion and thermophotovoltaic devices).In addition,both experimental facilities and measured results for different materials are summarized.Furthermore,future prospects in developing instrumentation and micro/nanostructured surfaces for practical applications are also outlined.This paper provides a comprehensive source of information for the application of micro/nanostructures in high-temperature energy conversion engineering.展开更多
Radiative thermoelectric energy converters, which include thermophotovoltaic cells, thermoradiative cells, electroluminescent refrigerators, and negative elec- troluminescent refrigerators, are semiconductor p-n devic...Radiative thermoelectric energy converters, which include thermophotovoltaic cells, thermoradiative cells, electroluminescent refrigerators, and negative elec- troluminescent refrigerators, are semiconductor p-n devices that either generate electricity or extract heat from a cold body while exchanging thermal radiation with their surroundings. If this exchange occurs at micro or nanoscale distances, power densities can be greatly enhanced and near-field radiation effects may improve performance. This review covers the fundamentals of near-field thermal radiation, photon entropy, and none- quilibrium effects in semiconductor diodes that underpin device operation. The development and state of the art of these near-field converters are discussed in detail, and remaining challenges and opportunities for progress are identified.展开更多
The burning of fossil fuels in industry results in significant carbon emissions,and the heat generated is often not fully utilized.For high-temperature industries,thermophotovoltaics(TPVs)is an effective method for wa...The burning of fossil fuels in industry results in significant carbon emissions,and the heat generated is often not fully utilized.For high-temperature industries,thermophotovoltaics(TPVs)is an effective method for waste heat recovery.This review covers two aspects of high-efficiency TPV systems and industrial waste heat applications.At the system level,representative results of TPV complete the systems,while selective emitters and photovoltaic cells in the last decade are compiled.The key points of components to improve the energy conversion efficiency are further analyzed,and the related micro/nano-fabrication methods are introduced.At the application level,the feasibility of TPV applications in high-temperature industries is shown from the world waste heat utilization situation.The potential of TPV in waste heat recovery and carbon neutrality is illustrated with the steel industry as an example.展开更多
Ultrathin cells have gained increasing attention due to their potential for reduced weight, reduced cost and increased flexibility. However, the light absorption in ultrathin cells is usually very weak compared to the...Ultrathin cells have gained increasing attention due to their potential for reduced weight, reduced cost and increased flexibility. However, the light absorption in ultrathin cells is usually very weak compared to the corresponding bulk cells. To achieve enhanced photon absorption in ultrathin thermophotovoltaic （TPV） cells, this work proposed a film-coupled metamaterial structure made of nanometer-thick gallium antimonide （GaSh） layer sandwiched by a top one-dimensional （1D） metallic grating and a bottom metal film. The spectral normal absorptance of the proposed structure was calculated using the rigorous coupled-wave algorithm （RCWA） and the absorption enhancement was elucidated to be attributed to the excitations of magnetic polariton （MP）, surface plasmon polariton （SPP）, and Fabry-Perot （FP） resonance. The mechanisms of MP, SPP, and FP were further confirmed by an inductor-capacitor circuit model, disper- sion relation, and phase shift, respectively. Effects of grating period, width, spacer thickness, as well as incidence angle were discussed. Moreover, short-circuit current density, open-circuit voltage, output electric power,and conversion efficiency were evaluated for the ultrathin GaSb TPV cell with a film-coupled metamaterial structure. This work will facilitate the development of next- generation low-cost ultrathin infrared TPV cells.展开更多
Single-junction,lattice-mismatched In0.69Ga0.31As thermophotovoltaic（TPV） devices each with a bandgap of 0.6 eV are grown on InP substrate by metal-organic chemical vapour deposition（MOCVD）.Compositionally undulat...Single-junction,lattice-mismatched In0.69Ga0.31As thermophotovoltaic（TPV） devices each with a bandgap of 0.6 eV are grown on InP substrate by metal-organic chemical vapour deposition（MOCVD）.Compositionally undulating stepgraded InAsyP1-y buffer layers with a lattice mismatch of ～1.2% are used to mitigate the effect of lattice mismatch between the device layers and the InP substrate.With an optimized buffer thickness,the In0.69Ga0.31As active layers grown on the buffer display a high crystal quality with no measurable tetragonal distortion.High-performance single-junction devices are demonstrated,with an open-circuit voltage of 0.215 V and a photovoltaic conversion efficiency of 6.9% at a short-circuit current density of 47.6 mA/cm2,which are measured under the standard solar simulator of air mass 1.5-global（AM 1.5 G）.展开更多
A model for predicting the performance of the emitter in the solar thermophotovoltaic (STPV) system is presented in this article. The effect of non-parallelism of sun rays on concentration capability is numerically ca...A model for predicting the performance of the emitter in the solar thermophotovoltaic (STPV) system is presented in this article. The effect of non-parallelism of sun rays on concentration capability is numerically calculated,also the flow field in the emitter cavity and the temperature distribution of the emitter with different inlet conditions are compared. Numerical results show that free convection of the air inside the emitter cavity has great effect on the emitter temperature and may reduce the electricity output of the cells. At last,a new kind of selective film is put forward. Through optimizing the cut-off wavelength of a selective film,radiation loss is further reduced and system efficiency is improved.展开更多
基金the National Natural Science Foundation of China (Grant No. 50776047)Natural Science Foundation of Jiangsu Province (Grant No. BK2007726)
文摘The spectral control is widely incorporated with the thermophotovoltaic (TPV) technology to improve the optical-electric conversion efficiency of the whole sys- tem. In order to match with GaSb photovoltaic cell, an 8-layer one-dimensional photonic crystals (PC) filter structure was designed as quarter-wave periodic structure by selecting silicon (Si) and silicon dioxide (SiO2) as candidate materials. The multilayer Si/SiO2 structure was developed for the matching filter to simulta- neously realize the optimal matching with the spectral distribution of the high temperature emitter and the quantum efficiency of GaSb cell. The physical vapor deposition (PVD) method was used to fabricate the optical filter and the normal incidence optical property of the filter was measured within the spectral range from 0.7 to 3.3 μm. These experimental data were used to predict the spectral control performance in a TPV system. Finally, temperature performance experiments were carried out to establish its withstanding performance in high temperature envi- ronment.
基金supported by the National Natural Science Foundation of China(Grant No.52276075)sponsored by the Natural Science Foundation of Shanghai(Grant No.21ZR1433500)。
文摘Near-field thermophotovoltaic(NTPV)devices comprising a SiC-hBN-graphene emitter and a graphene-InSb cell with gratings are designed to enhance the performance of the NTPV systems.Fluctuational electrodynamics and rigorous coupled-wave analysis are employed to calculate radiative heat transfer fluxes.It is found that the NTPV systems with two graphene ribbons perform better due to the graphene strong coupling effects.The effects of graphene chemical potential are discussed.It is demonstrated that near-field radiative heat transfer of thermophotovoltaic devices is enhanced by the coupling of surface plasmon polaritons,surface phonon polaritons,hyperbolic phonon polaritons,and magnetic polaritons caused by the graphene strong coupling effects.Rabi splitting frequency of different polaritons is calculated to quantify the mutual interaction of graphene strong coupling effects.Finally,the effects of cell grating filling ratio are investigated.The excitation of magnetic polaritons is affected by the graphene ribbon and the cell filling ratio.This investigation provides a new explanation of the enhancement mechanism of graphene-assisted thermophotovoltaic systems and a novel approach for improving the output power of the near-field thermophotovoltaic system.
基金the National Natural Science Foundation of China(Grant No.52276075)the Natural Science Foundation of Shanghai(Grant No.21ZR1433500)。
文摘The near-field effect can be used to improve the output power of the near-field thermophotovoltaic device(NTPV).The nearfield radiative heat transfer in the near-field thermophotovoltaic device can be enhanced by the excitation of hyperbolic modes and the coupling of surface plasmon polaritons.In this study,we design a two-body near-field thermophotovoltaic system based on hyperbolic metamaterial.The multilayer structure on the emitter is composed of Ga-doped ZnO(GZO)and hafnium dioxide(HfO2).The gratings are on the InAs photovoltaic cell.Fluctuational electrodynamics and rigorous coupled-wave method are employed to calculate radiative heat transfer.It is found that the NTPV system with multiple microstructures performs better than the NTPV system just with single micro-structures.This NTPV system performs better in a wider vacuum gap.The output power and efficiency are enhanced by the GZO-HfO2surface plasmon polaritons in multilayer structure.The gratings can monitor the spectral heat flux to match the cell band gap to enhance the performance of the near-field thermophotovoltaic system.This investigation provides a novel approach for improving the output power of a two-body near-field thermophotovoltaic system.
基金This work was supported by the China Scholarship Council(No.201806320236)the Academic Award for Outstanding Doctoral Candidates of Zhejiang University(No.2018071)+1 种基金the Key Research and Development Program of Ningxia Hui Autonomous Region(No.2018BCE01004)the US Department of Energy's Office of Energy Efficiency and Renewable Energy(EERE)under the Solar Energy Technologies Office.
文摘Micro/nanostructures play a key role in tuning the radiative properties of materials and have been applied to high-temperature energy conversion systems for improved performance.Among the various radiative properties,spectral emittance is of integral importance for the design and analysis of materials that function as radiative absorbers or emitters.This paper presents an overview of the spectral emittance measurement techniques using both the direct and indirect methods.Besides,several micro/nanostructures are also introduced,and a special emphasis is placed on the emissometers developed for characterizing engineered micro/nanostructures in high-temperature applications(e.g.,solar energy conversion and thermophotovoltaic devices).In addition,both experimental facilities and measured results for different materials are summarized.Furthermore,future prospects in developing instrumentation and micro/nanostructured surfaces for practical applications are also outlined.This paper provides a comprehensive source of information for the application of micro/nanostructures in high-temperature energy conversion engineering.
文摘Radiative thermoelectric energy converters, which include thermophotovoltaic cells, thermoradiative cells, electroluminescent refrigerators, and negative elec- troluminescent refrigerators, are semiconductor p-n devices that either generate electricity or extract heat from a cold body while exchanging thermal radiation with their surroundings. If this exchange occurs at micro or nanoscale distances, power densities can be greatly enhanced and near-field radiation effects may improve performance. This review covers the fundamentals of near-field thermal radiation, photon entropy, and none- quilibrium effects in semiconductor diodes that underpin device operation. The development and state of the art of these near-field converters are discussed in detail, and remaining challenges and opportunities for progress are identified.
基金supported by the National Natural Science Foundation of China(No.52227813)China Postdoctoral Science Foundation(Nos.2023M740905,2023T160164)+3 种基金National Key ResearchDevelopment Program of China(No.2022YFE0210200)Natural Science Foundation of Heilongjiang Province(No.LH2023E043)the Fundamental Research Funds for the Central Universities(Nos.2022ZFJH04,HIT.OCEF.2021023)。
文摘The burning of fossil fuels in industry results in significant carbon emissions,and the heat generated is often not fully utilized.For high-temperature industries,thermophotovoltaics(TPVs)is an effective method for waste heat recovery.This review covers two aspects of high-efficiency TPV systems and industrial waste heat applications.At the system level,representative results of TPV complete the systems,while selective emitters and photovoltaic cells in the last decade are compiled.The key points of components to improve the energy conversion efficiency are further analyzed,and the related micro/nano-fabrication methods are introduced.At the application level,the feasibility of TPV applications in high-temperature industries is shown from the world waste heat utilization situation.The potential of TPV in waste heat recovery and carbon neutrality is illustrated with the steel industry as an example.
文摘Ultrathin cells have gained increasing attention due to their potential for reduced weight, reduced cost and increased flexibility. However, the light absorption in ultrathin cells is usually very weak compared to the corresponding bulk cells. To achieve enhanced photon absorption in ultrathin thermophotovoltaic （TPV） cells, this work proposed a film-coupled metamaterial structure made of nanometer-thick gallium antimonide （GaSh） layer sandwiched by a top one-dimensional （1D） metallic grating and a bottom metal film. The spectral normal absorptance of the proposed structure was calculated using the rigorous coupled-wave algorithm （RCWA） and the absorption enhancement was elucidated to be attributed to the excitations of magnetic polariton （MP）, surface plasmon polariton （SPP）, and Fabry-Perot （FP） resonance. The mechanisms of MP, SPP, and FP were further confirmed by an inductor-capacitor circuit model, disper- sion relation, and phase shift, respectively. Effects of grating period, width, spacer thickness, as well as incidence angle were discussed. Moreover, short-circuit current density, open-circuit voltage, output electric power,and conversion efficiency were evaluated for the ultrathin GaSb TPV cell with a film-coupled metamaterial structure. This work will facilitate the development of next- generation low-cost ultrathin infrared TPV cells.
基金Project supported by the National Basic Research Program of China (Grant No. 61176128)the Knowledge Innovation Project of the Chinese Academy of SciencesSuzhou Municipal Solar Cell Research Project,China (Grant No. SYG201145)
文摘Single-junction,lattice-mismatched In0.69Ga0.31As thermophotovoltaic（TPV） devices each with a bandgap of 0.6 eV are grown on InP substrate by metal-organic chemical vapour deposition（MOCVD）.Compositionally undulating stepgraded InAsyP1-y buffer layers with a lattice mismatch of ～1.2% are used to mitigate the effect of lattice mismatch between the device layers and the InP substrate.With an optimized buffer thickness,the In0.69Ga0.31As active layers grown on the buffer display a high crystal quality with no measurable tetragonal distortion.High-performance single-junction devices are demonstrated,with an open-circuit voltage of 0.215 V and a photovoltaic conversion efficiency of 6.9% at a short-circuit current density of 47.6 mA/cm2,which are measured under the standard solar simulator of air mass 1.5-global（AM 1.5 G）.
基金Supported by the Natural Science Foundation of Jiangsu Province of China (Grant No. BK2007726)
文摘A model for predicting the performance of the emitter in the solar thermophotovoltaic (STPV) system is presented in this article. The effect of non-parallelism of sun rays on concentration capability is numerically calculated,also the flow field in the emitter cavity and the temperature distribution of the emitter with different inlet conditions are compared. Numerical results show that free convection of the air inside the emitter cavity has great effect on the emitter temperature and may reduce the electricity output of the cells. At last,a new kind of selective film is put forward. Through optimizing the cut-off wavelength of a selective film,radiation loss is further reduced and system efficiency is improved.
