Frequency-dependent light emission and extinction of electroluminescent ZnS:Cu phosphor

Alternating current thick film light emitters has been prepared by using ZnS:Cu commercial phosphors and thick film technology. The dependence of electroluminescent emission on excitation frequency and voltage applied to light emission devices was studied. Electroluminescent spectra were decomposed into four Gaussians corresponding to emission transitions and their respective peak position wavelengths and amplitudes were analyzed as a function of the applied voltage frequency. The time constants associated to every of those centres have been calculated by determining the extinction times of the related light emission. A straight relationship between electroluminescence extinction time and frequency response for each emission wavelength has been found.