Effects of prepoling and polarization on photoemission from ferroelectric ceramics

We describe the photoemission of lanthanum-doped lead zirconate titanate when illuminated with 355 nm radiation, with/without prepoling and with/without the application of a polarizing field. To explain the different behaviors observed, we propose a physical picture based on the defects moving toward the surface and the donor electrons squeezing into a very thin layer at the surface. The model and the experimental results indicate that ferroelectric ceramics could become interesting photoemitters.