Certain oxide phosphors have been observed to exhibit substantial electroluminescence (EL) in high electric fields. This electroluminescence may be induced either by an alternating field, in which case insulating films may be interposed between the phosphor and the electrodes, or by a direct field, in which case an insulating film between the electrodes is not permissible. The voltage required is about 20 times that needed for equal brightness in commercial EL lamps using copper-activated zinc sulfide phosphors.