Ceramic electrospun nanofibers as selective emitters for thermophotovoltaic energy conversion

Ceramic nanofibers were produced by electrospinning and characterized with electron microscopy, X-ray diffraction, FTIR, and X-ray photoelectron spectroscopy. Rare earth compounds were incorporated in the ceramic nanofibers in order to selectively modify the optical properties of the ceramic electrospun nanofibers. Titania electrospun fibers were studied. X-ray diffraction showed the titania nanofiber annealed at 773 K had the anatase crystal structure, and annealing at 1173 K produced the rutile crystal structure. In order to modify the optical properties, erbia was incorporated into Titania nanofibers. Temperature-dependent emission spectra showed that the erbia-containing nanofibers emit selectively in the near-infrared when convectively heated by hot gas. The electrical power generated by a GaSb photodetector was measured as a function of temperature. Such ceramic nanofibers can be used in thermophotovoltaic energy conversion technology to generate electrical energy from relatively low temperature heat sources, which are presently wasted.