The Experts below are selected from a list of 246 Experts worldwide ranked by ideXlab platform
Jared Schwede - One of the best experts on this subject based on the ideXlab platform.
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photon enhanced Thermionic Emission from heterostructures with low interface recombination
Nature Communications, 2013Co-Authors: Jared Schwede, Tomas Sarmiento, Vijay K Narasimhan, Samuel Rosenthal, Daniel C RileyAbstract:Photon-enhanced Thermionic Emission is a method of solar-energy conversion that promises to combine photon and thermal processes into a single mechanism, overcoming fundamental limits on the efficiency of photovoltaic cells. Photon-enhanced Thermionic Emission relies on vacuum Emission of photoexcited electrons that are in thermal equilibrium with a semiconductor lattice, avoiding challenging non-equilibrium requirements and exotic material properties. However, although previous work demonstrated the photon-enhanced Thermionic Emission effect, efficiency has until now remained very low. Here we describe electron-Emission measurements on a GaAs/AlGaAs heterostructure that introduces an internal interface, decoupling the basic physics of photon-enhanced Thermionic Emission from the vacuum Emission process. Quantum efficiencies are dramatically higher than in previous experiments because of low interface recombination and are projected to increase another order of magnitude with more stable, low work-function coatings. The results highlight the effectiveness of the photon-enhanced Thermionic Emission process and demonstrate that efficient photon-enhanced Thermionic Emission is achievable, a key step towards realistic photon-enhanced Thermionic Emission based energy conversion. By having the electrons and lattice at high temperature, photon-enhanced Thermionic Emission offers improved electron extraction energy in solar conversion devices. Schwede et al.use a heterostructure design to introduce an internal interface, showing higher quantum efficiencies than previous experiments.
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photon enhanced Thermionic Emission for solar concentrator systems
Nature Materials, 2010Co-Authors: Jared Schwede, Daniel C Riley, Igor Bargatin, Brian E Hardin, Samuel RosenthalAbstract:The conversion of solar energy into electricity usually occurs either electrically or through thermal conversion. A new mechanism, photon-enhanced Thermionic Emission, which combines electric as well as thermal conversion mechanisms, is now shown to lead to enhanced conversion efficiencies that potentially could even exceed the theoretical limits of conventional photovoltaic cells.
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Thermionic Emission from microfabricated silicon carbide filaments
2009Co-Authors: Igor Bargatin, Jared Schwede, J Provine, W A Clay, Roya Maboudian, Nicholas A MeloshAbstract:We have measured Thermionic Emission from microfabricated 3C silicon carbide filaments. When the filaments were heated resistively, the emitted current grew approximately exponentially with the applied heating power, consistent with the Thermionic Emission mechanism. Using photoEmission, we have also determined the work function of cesiated 3C-SiC to be approximately 1.65 eV at room temperature. These measurements demonstrate the potential of SiC for electron Emission applications and, in particular, for microfabricated Thermionic energy converters.
Daniel C Riley - One of the best experts on this subject based on the ideXlab platform.
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photon enhanced Thermionic Emission from heterostructures with low interface recombination
Nature Communications, 2013Co-Authors: Jared Schwede, Tomas Sarmiento, Vijay K Narasimhan, Samuel Rosenthal, Daniel C RileyAbstract:Photon-enhanced Thermionic Emission is a method of solar-energy conversion that promises to combine photon and thermal processes into a single mechanism, overcoming fundamental limits on the efficiency of photovoltaic cells. Photon-enhanced Thermionic Emission relies on vacuum Emission of photoexcited electrons that are in thermal equilibrium with a semiconductor lattice, avoiding challenging non-equilibrium requirements and exotic material properties. However, although previous work demonstrated the photon-enhanced Thermionic Emission effect, efficiency has until now remained very low. Here we describe electron-Emission measurements on a GaAs/AlGaAs heterostructure that introduces an internal interface, decoupling the basic physics of photon-enhanced Thermionic Emission from the vacuum Emission process. Quantum efficiencies are dramatically higher than in previous experiments because of low interface recombination and are projected to increase another order of magnitude with more stable, low work-function coatings. The results highlight the effectiveness of the photon-enhanced Thermionic Emission process and demonstrate that efficient photon-enhanced Thermionic Emission is achievable, a key step towards realistic photon-enhanced Thermionic Emission based energy conversion. By having the electrons and lattice at high temperature, photon-enhanced Thermionic Emission offers improved electron extraction energy in solar conversion devices. Schwede et al.use a heterostructure design to introduce an internal interface, showing higher quantum efficiencies than previous experiments.
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photon enhanced Thermionic Emission for solar concentrator systems
Nature Materials, 2010Co-Authors: Jared Schwede, Daniel C Riley, Igor Bargatin, Brian E Hardin, Samuel RosenthalAbstract:The conversion of solar energy into electricity usually occurs either electrically or through thermal conversion. A new mechanism, photon-enhanced Thermionic Emission, which combines electric as well as thermal conversion mechanisms, is now shown to lead to enhanced conversion efficiencies that potentially could even exceed the theoretical limits of conventional photovoltaic cells.
Samuel Rosenthal - One of the best experts on this subject based on the ideXlab platform.
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photon enhanced Thermionic Emission from heterostructures with low interface recombination
Nature Communications, 2013Co-Authors: Jared Schwede, Tomas Sarmiento, Vijay K Narasimhan, Samuel Rosenthal, Daniel C RileyAbstract:Photon-enhanced Thermionic Emission is a method of solar-energy conversion that promises to combine photon and thermal processes into a single mechanism, overcoming fundamental limits on the efficiency of photovoltaic cells. Photon-enhanced Thermionic Emission relies on vacuum Emission of photoexcited electrons that are in thermal equilibrium with a semiconductor lattice, avoiding challenging non-equilibrium requirements and exotic material properties. However, although previous work demonstrated the photon-enhanced Thermionic Emission effect, efficiency has until now remained very low. Here we describe electron-Emission measurements on a GaAs/AlGaAs heterostructure that introduces an internal interface, decoupling the basic physics of photon-enhanced Thermionic Emission from the vacuum Emission process. Quantum efficiencies are dramatically higher than in previous experiments because of low interface recombination and are projected to increase another order of magnitude with more stable, low work-function coatings. The results highlight the effectiveness of the photon-enhanced Thermionic Emission process and demonstrate that efficient photon-enhanced Thermionic Emission is achievable, a key step towards realistic photon-enhanced Thermionic Emission based energy conversion. By having the electrons and lattice at high temperature, photon-enhanced Thermionic Emission offers improved electron extraction energy in solar conversion devices. Schwede et al.use a heterostructure design to introduce an internal interface, showing higher quantum efficiencies than previous experiments.
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photon enhanced Thermionic Emission for solar concentrator systems
Nature Materials, 2010Co-Authors: Jared Schwede, Daniel C Riley, Igor Bargatin, Brian E Hardin, Samuel RosenthalAbstract:The conversion of solar energy into electricity usually occurs either electrically or through thermal conversion. A new mechanism, photon-enhanced Thermionic Emission, which combines electric as well as thermal conversion mechanisms, is now shown to lead to enhanced conversion efficiencies that potentially could even exceed the theoretical limits of conventional photovoltaic cells.
Igor Bargatin - One of the best experts on this subject based on the ideXlab platform.
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Effect of illlumination on Thermionic Emission from microfabricated silicon carbide structures
2011 16th International Solid-State Sensors Actuators and Microsystems Conference, 2011Co-Authors: Igor Bargatin, J Provine, Roya Maboudian, Nicholas A Melosh, M.l L. Brongersma, Z.x. Shen, R.t. HoweAbstract:Microfabricated Thermionic emitters form a crucial part of Thermionic energy converters, which could find applications in future concentrated solar thermal power plants. Here we report a new stress-relieved design for p-doped and n-doped silicon carbide (SiC) emitters, measurements of their Thermionic Emission and work functions at temperatures of up to 2900K, and the effect of optical irradiation on both types of SiC emitters. We also report the first observation of the photon-enhanced Thermionic Emission (PETE) in a thin-film microfabricated emitter.
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photon enhanced Thermionic Emission for solar concentrator systems
Nature Materials, 2010Co-Authors: Jared Schwede, Daniel C Riley, Igor Bargatin, Brian E Hardin, Samuel RosenthalAbstract:The conversion of solar energy into electricity usually occurs either electrically or through thermal conversion. A new mechanism, photon-enhanced Thermionic Emission, which combines electric as well as thermal conversion mechanisms, is now shown to lead to enhanced conversion efficiencies that potentially could even exceed the theoretical limits of conventional photovoltaic cells.
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Thermionic Emission from microfabricated silicon carbide filaments
2009Co-Authors: Igor Bargatin, Jared Schwede, J Provine, W A Clay, Roya Maboudian, Nicholas A MeloshAbstract:We have measured Thermionic Emission from microfabricated 3C silicon carbide filaments. When the filaments were heated resistively, the emitted current grew approximately exponentially with the applied heating power, consistent with the Thermionic Emission mechanism. Using photoEmission, we have also determined the work function of cesiated 3C-SiC to be approximately 1.65 eV at room temperature. These measurements demonstrate the potential of SiC for electron Emission applications and, in particular, for microfabricated Thermionic energy converters.
Abraham Kribus - One of the best experts on this subject based on the ideXlab platform.
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Solar Electricity with Photon-Enhanced Thermionic Emission (PETE)
Light Energy and the Environment, 2014Co-Authors: Abraham Kribus, Gideon Segev, Yossi RosenwaksAbstract:Photon-enhanced Thermionic Emission combines both photonic and thermal excitation to emit electrons from a semiconductor cathode. Theoretical conversion efficiency exceeds 45% at 1,000 suns, and over 50% with a second stage thermal converter.
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efficiency of photon enhanced Thermionic Emission solar converters
Solar Energy Materials and Solar Cells, 2012Co-Authors: Gideon Segev, Y Rosenwaks, Abraham KribusAbstract:Abstract Photon Enhanced Thermionic Emission (PETE) is a recently proposed novel concept in solar energy conversion, combining thermal and photovoltaic carrier excitation with Thermionic Emission. A recent study has shown that PETE conversion efficiencies can theoretically rise above 40% at concentration of 1000 suns. We analyze two major aspects missing from previous treatment of PETE conversion efficiency: changes in the cathode's conduction band carrier concentration with the electrical operating point; and determination of the cathode temperature from a full thermal energy balance. The results show that the conversion efficiency is a monotonically increasing function of temperature, and a monotonically decreasing function of the cathode electron affinity. It is shown that PETE converter efficiency according to the modified model is higher than previously reported, but achieving very high efficiencies of over 40% requires high temperatures that may be difficult in practical implementation.
