Low voltage electron emission from Pb(Zr/sub x/Ti/sub 1-x/)O/sub 3/-based thin film cathodes

Electron emission from ferroelectric thin films (/spl les/1 /spl mu/m thick) is demonstrated. In addition, electron energy distributions have been measured using an Auger Electron Spectrometer (AES). The electron emission measurements were performed using ferroelectric cathodes based on thin Pb(Zr/sub 0.53/Ti/sub 0.47/)O/sub 3/ (PZT) films and 80-110 /spl mu/m Pb/sub 0.93/La/sub 0.07/ (Z/sub 0.53/Ti/sub 0.47/)O/sub 3/ (PLZT) layered capacitors with Pt top and bottom electrodes. Current densities in the range of 0.5-1.5 mA/cm/sup 2/ were measured from the PLZT cathodes excited with 100-400 volt pulses, which produced electrons of about 265 eV with a narrow energy distribution (FWHM of about 30 eV). On the other hand, current densities in the range 0.07-0.15 /spl mu/A/cm/sup 2/ were measured for thin film PZT-based cathodes excited with pulses in the range 10-40 volts. The initial results suggest that the electron emission current may depend, among other factors, on the thickness of the ferroelectric layer, the applied excitation voltage, and the interval between the polarizing and switching pulses.