Charge injbction and electroluminescence threshold field in polymmic material under prebreakdown a.c. field

Luminescence and space charge injection have been reported to occur during long-term degradation of polymeric materials under a prebreakdown field /1-3/. The nain hypothesis, concerning the deterioration mechanisms of the lattice, in volves hot electrons processes and/or photodegradation resulting from absorption of recombination-generated UV radiation. In this context, one challenge is to study the correlation between electroluminescence and charge injection. We pre sent, in the following, two very sensitive detection setups, allowing the determi nation of the electric threshold field of these phenouiena. Results are presen ted for two dielectric materials : polyethylene and epoxy resin.