Behaviors of different electrode-LDPE contacts and its effect on surface electroluminescence characteristics

The contact barrier between the electrode and insulating material directly affects the current injection, and further affects the electroluminescence (EL) from the material surface. In this paper, an experimental setup is designed to investigate the contact resistance between metal electrode and solid material, and the contact resistance between low density polyethylene (LDPE) with/without sputtered metal film electrode and metal electrode are measured by that. The influence of sputtered film electrode on EL characteristics from the surface of LDPE is also discussed. Experimental results show that the contact resistance becomes smaller with sputtered metal film electrode, and the EL initial voltage and intensity of LDPE with the sputtered film electrode is smaller than that of LDPE without sputtered electrode. It is considered that the sputtered films electrode will improve the contact status between electrode and LDPE and induce the reduction of contact resistance and EL initial voltage and it also increases the surface state density of LDPE material, which would induce the reduction of EL intensity.