Systems and apparatus to generate electrical power from aircraft engine heat are described herein. An example aircraft engine described herein includes a gas turbine engine having an engine housing. The engine housing defines a flow path through a combustion chamber and a core exhaust cavity. The example aircraft engine also includes an energy-generating cell coupled to a portion of the engine housing defining the core exhaust cavity. The energy-generating cell is to generate electrical energy from high temperature fluid in the core exhaust cavity.

A selective emitter exhibiting heat resistance up to 1000° C., comprising a metal body, a first dielectric layer provided on one surface of the metal body, a composite layer provided on another surface of the first dielectric layer at an opposite side to the metal body side, and a second dielectric layer provided on another surface of the composite layer at an opposite side to the first dielectric layer, the composite layer being a layer provided with a metal or semiconductor dispersed in an oxide of the metal or the semiconductor.

A selective emitter exhibiting heat resistance up to 1000° C., comprising a metal body, a first dielectric layer provided on one surface of the metal body, a composite layer provided on another surface of the first dielectric layer at an opposite side to the metal body side, and a second dielectric layer provided on another surface of the composite layer at an opposite side to the first dielectric layer, the composite layer being a layer provided with a metal or semiconductor dispersed in an oxide of the metal or the semiconductor.

A near-field ThermoPhotoVoltaic system comprises a hot emitter and a cold absorbing PhotoVoltaic cell separated by a small gap. The emitter emits hot photons and includes a polaritonic material that supports a surface-polaritonic mode. The PhotoVoltaic cell has a metallic back electrode and includes a semiconductor that absorbs the photons and supports guided photonic modes. The surface-polaritonic mode and the first guided photonic mode resonantly couple at a frequency slightly above the semiconductor bandgap. The system material and geometrical parameters are such that the surface-polaritonic mode and the first guided photonic mode are approximately impedance-matched, so that power is transmitted at frequencies just above the semiconductor bandgap, even for relatively large gap widths, while the power transmitted at other frequencies is relatively small, leading to high system efficiency. Also described the PhotoVoltaic cell's front electrode, which may include highly-doped semiconductor regions, thin conducting oxide or silver films, or graphene layers.

A near-field ThermoPhotoVoltaic system comprises a hot emitter and a cold absorbing PhotoVoltaic cell separated by a small gap. The emitter emits hot photons and includes a polaritonic material that supports a surface-polaritonic mode. The PhotoVoltaic cell has a metallic back electrode and includes a semiconductor that absorbs the photons and supports guided photonic modes. The surface-polaritonic mode and the first guided photonic mode resonantly couple at a frequency slightly above the semiconductor bandgap. The system material and geometrical parameters are such that the surface-polaritonic mode and the first guided photonic mode are approximately impedance-matched, so that power is transmitted at frequencies just above the semiconductor bandgap, even for relatively large gap widths, while the power transmitted at other frequencies is relatively small, leading to high system efficiency. Also described the PhotoVoltaic cell's front electrode, which may include highly-doped semiconductor regions, thin conducting oxide or silver films, or graphene layers.

Method and system for wavelength thermophotovoltaic (WTPV) power generation. In one embodiment, the system comprises a refractory waveguide that collects broadband infrared light generated by a heat source; a filter that filters the collected broadband infrared light to generate narrow-band infrared light; and a thermophotovoltaic (TPV) converter, thermally de-coupled from the heat source, that receives the narrow-band infrared light and converts the received narrow-band infrared light to electrical power.

Method and system for wavelength thermophotovoltaic (WTPV) power generation. In one embodiment, the system comprises a refractory waveguide that collects broadband infrared light generated by a heat source; a filter that filters the collected broadband infrared light to generate narrow-band infrared light; and a thermophotovoltaic (TPV) converter, thermally de-coupled from the heat source, that receives the narrow-band infrared light and converts the received narrow-band infrared light to electrical power.

A solar thermophotovoltaic system includes a heat exchange pipe containing a heat exchange fluid, and a thin-film integrated spectrally-selective plasmonic absorber emitter (ISSAE) in direct contact with an outer surface of the heat exchange pipe, the ISSAE including an ultra-thin non-shiny metal layer comprising a metal strongly absorbing in a solar spectral range and strongly reflective in an infrared spectral range, the metal layer having an inner surface in direct contact with an outer surface of the heat exchange pipe. The system further includes a photovoltaic cell support structure having an inner surface in a concentric configuration surrounding at least a portion of the ISSAE; and an airgap separating the support structure and the outer surface of the metal layer. The support structure includes a plurality of photovoltaic cells arranged on a portion of the inner surface of the support structure and configured to receive emissions from the ISSAE, and a solar energy collector/concentrator configured to allow solar radiation to impinge a portion of the metal layer.

A solar thermophotovoltaic system includes a heat exchange pipe containing a heat exchange fluid, and a thin-film integrated spectrally-selective plasmonic absorber emitter (ISSAE) in direct contact with an outer surface of the heat exchange pipe, the ISSAE including an ultra-thin non-shiny metal layer comprising a metal strongly absorbing in a solar spectral range and strongly reflective in an infrared spectral range, the metal layer having an inner surface in direct contact with an outer surface of the heat exchange pipe. The system further includes a photovoltaic cell support structure having an inner surface in a concentric configuration surrounding at least a portion of the ISSAE; and an airgap separating the support structure and the outer surface of the metal layer. The support structure includes a plurality of photovoltaic cells arranged on a portion of the inner surface of the support structure and configured to receive emissions from the ISSAE, and a solar energy collector/concentrator configured to allow solar radiation to impinge a portion of the metal layer.

A photovoltaic power system includes a photofuel having a molecular structure to emit light, and a receptacle including the photofuel disposed within. One or more photovoltaic cells are positioned within the receptacle to receive light emitted from the photofuel, and a negative electrode is coupled to the one or more photovoltaic cells. A positive electrode is coupled to the one or more photovoltaic cells to produce an electrical potential between the negative electrode and the positive electrode when a photocurrent is generated by the one or more photovoltaic cells in response to the one or more photovoltaic cells receiving the light emitted from the photofuel.