A new flat back-light excited by plasma employing different conductive materials as the external electrode was developed. This back-light is composed of two sealed flat glasses in which the pure Xe (at pressure of 200 Torr) was inflated and a layer of phosphor was coated. A water film being considered as electrode was sealed on the out surface of the upper glass substrate, and an ITO film being considered as conductive medium was added on the out surfaces of the lower glass substrate by using the transparent conductive tape, where the glass with thickness of 1.1 mm was used as the dielectric barrier discharge layer. The white light was available by exciting the phosphor layer with the plasmas introduced by high-frequency voltage, whose luminance was 4 000 cd/m2 accompanied with the lighting homogeneity over than 92%. The experimental results show that the most suitable driving frequency was 9.6 kHz.