Ceramic film, method for manufacturing the same, emitter, and thermophotovoltaic power generation device
A ceramic film for a TPV power generation device, the ceramic film having a sufficiently high strength thus making it possible to obtain a desirable radiation spectrum, is provided. A ceramic film ( 20 ) according to an example embodiment is a ceramic film that is formed on a base material and has pores, and includes a plurality of high-density regions ( 1 ) having a density higher than an average density of the entire ceramic film and a plurality of low-density regions ( 2 ) having a density lower than the average density of the entire ceramic film. Further, the high-density regions ( 1 ) and the low-density regions ( 2 ) are stacked in layers. The ceramic film is composed of an oxide ceramic containing a rare-earth element.
1 . A ceramic film that is formed on a thermal source, converts heat from the thermal source into an infrared light and has pores, the ceramic film comprising:
a plurality of high-density regions, which are small porosity regions having a density higher than an average density of the entire ceramic film; and
a plurality of low density regions, which are large porosity regions having a density lower than the average density of the entire ceramic film, wherein
the plurality of high density regions and the plurality of low density regions are alternatively stacked in layers.
2 . The ceramic film according to claim 1 , wherein the ceramic film is composed of an oxide ceramic containing a rare-earth element.
3 . The ceramic film according to claim 2 , wherein a composition of the ceramic film is R 3 Ga 5 O 12 or R 3 Al 5 O 12 (R: rare-earth element).
4 . The ceramic film according to claim 1 , wherein a particle diameter of each of ceramic particles in the plurality of low-density regions is 1 μm or less.
5 . The ceramic film according to claim 1 , wherein the ceramic film includes at least one of:
a plurality of low-density portions provided in the plurality of high-density regions; and
a plurality of high-density portions provided in the plurality of low-density regions.
6 . A method for manufacturing a ceramic film, the method comprising forming the ceramic film according to claim 1 on the thermal source by a plasma-assisted aerosol deposition method.
7 . The method for manufacturing the ceramic film according to claim 6 , comprising moving the thermal source relative to a nozzle that ejects aerosol containing raw powder to form the ceramic film on the thermal source.
8 . A thermophotovoltaic power generation device comprising:
an emitter formed of the ceramic film according to claim 1 formed on the thermal source, the emitter being configured to convert heat from the thermal source into the infrared light; and
a photoelectric conversion cell configured to convert the infrared light emitted from the emitter into an electric power.