Correlation between charge injection and electroluminescence in polyethylene under prebreakdown AC field

The space charge injection (SCI) and electroluminescence (EL) threshold fields in low-density polyethylene were investigated using highly sensitive detection setups. It is shown that space-charge injection set in before electroluminescence, in apparent contradiction with recent results concerning epoxy resin (see T. Beumann et al. 1987). An exact correlation between E/sub EL/ and E/sub SCI/ in polyethylene samples is not found, but the two effects take place in the low MV/cm range. The EL field values must be overestimated since SCI occurring at fields between 1 and 2 MV/cm tends to decrease the apparent field magnitude at the electrode tip.<
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