Modeling of a Pyroelectric Thin Film IR Imager

Abstract

In this work, the physical principles of an infrared imager based on electron emission from a ferroelectric thin film are investigated. Electric fields in the bulk and near the surface of the ferroelectric cathode were determined by solving Poisson's equation for a subsequent calculation of the emission current. In the mono-domain case, polarization was taken into account via the depolarization field. For multi-domain crystals, a non-degenerated p-type semiconductor was considered and polarization was described by the Devonshire-Ginsburg-Landau theory. We have shown that 90° domain walls intersecting the free surface induce centers of enhanced electron emission.

Keywords:

• Ferroelectric thin films
• potential barrier
• electron emission
• domain walls
• infrared imager

PACS:

• 73.30.+y
• 77.84.Dy
• 79.60.Jv
• 79.75.+g

Acknowledgments

This work was supported by the German Research Council (DFG) as part of the Research Group FOR 520 and by the NATO cooperation linkage grant 98.0987.