Electroluminescence in Mylar Films

Non-destructive electric breakdown through mylar films is associated with emission of an intense light flash. Within an active volume of about 4×10-8 cm3, L ≧ 109 photons are generated during a current pulse. L is proportional to the number of transported charge carriers (electrons) and independent from sample thickness. The emission spectrum is a superposition of ordinary mylar fluorescence centered at 370 nm and impurity bands at longer wavelengths. Interpretation is given in terms of acceleration of injected electrons within the positive cathodic spacecharge zone giving rise to both impact excitation and ionization, predominantly involving guest molecules.