Effects of a modified interface by silver nanoparticles/SiOC:H barrier layer against space charge injection under HVDC

Large number of studies describes phenomena associated with space charge build-up in polymeric materials and the incited consequences when high voltage direct current is imposed. Currently, the studies are oriented towards possibilities to minimize this drawback by addition of nanometric size inclusions into the bulk of the polymer material. One alternative approach is to tailor the interface of the insulating material with deep traps in order to limit and control charges injection before their penetration into the bulk. The barrier layer is composed of a mono plan of silver nanoparticles (AgNPs) embedded in an organosilicon matrix (SiOC:H) issued from hexamethyldisiloxane plasma polymerization and deposited at the surface of a low density polyethylene (LDPE) film. We present a comparative study of charge density distribution between reference LDPE films and a one-face tailored sample. The impact of the barrier layer was evaluated for applied fields in the range 10 to 50 kV/mm. Results show a high efficiency of the AgNPs/SiOC:H barrier layer to limit injection of space charge at the LDPE interface, for both positive and negative charges.