Electron emission from ferroelectric copolymer thin films of vinylidene fluoride and trifluoroethylene

摘要

Electron emission from ferroelectric copolymer thin films consisting of vinylidene fluoride and trifluoroethylene (PVDF-TrFE) are reported. The ～3 μm thick copolymer thin films were deposited by spin coating and were then annealed to improve their crystallinity. The as-annealed films exhibited an electron emission capability, as anticipated; an emission charge within the range from 122 to 308 pC/cycle occurs at a positive excitation voltage with different excitation frequencies. It was found that the electron emission process of the PVDF-TrFE thin films differs from the conventional ferroelectric electron emission. A possible emission mechanism is proposed, which suggests that an amorphous phase in the polymer films plays an important role in trapping and emitting electrons.