Hot-wall deposition using alternative source supply for SrS based electroluminescent phosphor thin films

Abstract

SrS based blue electroluminescent phosphor thin films, such as SrS : Ce and SrS : Cu, have been prepared by hot-wall deposition using alternating source supply. The SrS films deposited at 600°C are formed by columnar polycrystalline grains of 0.5–1 μm, mainly oriented along the [1 0 0] 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 0.10 lm/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.