Mechanism for the high voltage photovoltaic effect in ceramic ferroelectrics
- Cite this article as:
- Brody, P.S. & Crowne, F. JEM (1975) 4: 955. doi:10.1007/BF02660182
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The high-voltage photo-emf seen in poled ferroelectric ceramics is explained as the result of light-induced carriers screening an internal field within the bulk of individual grains. The internal field itself is explained as the result of the shielding by equilibrium carriers of the potential produced by the spontaneous polarization. Less-than-band-gap emf’s are produced across individual grains; these emf’s add in ceramics to produce the high-voltage photo-emf. A model yields the polarity and magnitude of the photo-emf, the dependence on temperature, remanent and spontaneous polarization, dielectric constant and grain size. The calculated and experimental results are in general agreement.