SrS based blue electroluminescent phosphor thin films, such as SrS : Cc and SrS : Cu, have been prepared by hot-wall deposition using alternating source supply. The SrS films deposited at 600 degrees C are formed by columnar polycrystalline grains of 0.5-1 mu m, mainly oriented along the [100] axis. From the average deposition rate, it is deduced that 1 Sr-S layer is deposited for one cycle of Sr and S vapor supply. The SrS : Cu,Cl device shows pure blue EL emission. The luminance and efficiency measured at 1 kHz are 100 cd/m(2) and 0.101 m/W, respectively. The SrS : Ce,Cl device shows a greenish-blue EL emission; however, the luminance and efficiency are much lower than those for the devices prepared by other deposition methods.