The size effect on pyroelectric response of ferroelectric nanowires and
nanotubes is analyzed. The pyroelectric coefficient strongly increases with the
wire radius decrease and diverges at critical radius Rcr corresponding to the
size-driven transition into paraelectric phase. Size-driven enhancement of
pyroelectric coupling leads to the giant pyroelectric current and voltage
generation by the polarized ferroelectric nanoparticles in response to the
temperature fluctuation. The maximum efficiency of the pyroelectric energy
harvesting and bolometric detection is derived, and is shown to approach the
Carnot limit for low temperatures.Comment: 17 pages, 4 figures, 1 Appendi