It is shown for Xe content ratio of 10% that the excited xenon atom density for the 1S(5) metastable state is 3.0 x 10(12) cm(-3) with a gap distance of 50 gm under a fixed gas pressure of 5.3 x 10(4) Pa in alternating current plasma display panels. It is observed that the VUV emission of 173 nm continues after its peak and lasts much longer than 147 nm emission. We also found that the time of VUV peak emission intensity for higher xenon mole fraction is longer. It is also concluded that the luminous efficiency is strongly dependent on the ion-induced secondary electron emission coefficient. (c) 2007 Elsevier B.V. All rights reserved.