A phosphor is provided which includes a general formula represented by CaxEuySi5O3\u2212aN6+b and the same crystal structure as the crystal represented by Ca2Si5O3N6. The plurality of electrode layers include a plurality of alternating layers of active electrodes extending inwardly from alternating ends of the ceramic capacitor body. A gate voltage is about equal to or greater than a breakdown voltage of the gate dielectric in order to break down the gate dielectric into a breakdown state.