Electroluminescence and space charge in insulating materials under DC stress

Electroluminescence (EL) in organic materials is nowadays a popular subject thanks to the organic light emitting devices. In the latter, injection and transport of electrons and holes are tailored to enhance the radiative recombination of electrical charges. Similar kinds of electronic processes occur in large band gap materials telling us that electronic excitations have been promoted. EL analysis provides an insight into electrical ageing and breakdown because these states might decay by specific route which could produce damage. Techniques with the ability to spatially resolve the space charge distribution in films have been used to investigate the EL excitation mechanisms in polyethylene and polyethylene naphthalate films submitted to DC stress.