Contact-injected space charge in pet

We conclude that, at fields ≳ 1 MV/cm and temperatures ≳ RT, a number of metal cathodes, notably Aℓ, are capable of injecting electrons representing a significant fraction of CV into PET. At RT, the ensuing conduction current continues decaying (we have not observed a steady value at RT). Most of the injected charge is stored in traps ≃ 1. 8 eV deep close to the cathode. In aluminized PET capacitors under high DC bias, this space charge must adversely affect both the power factor and the breakdown strength. Injection of holes from Au and other metals at RT and comparable stress is much weaker. Since Au injects no electrons, one would expect capacitors with Au electrodes to offer superior performance.