Crystallinity of ZnS:Tb,F thin films and characteristics of green-color thin-film electroluminescent devices prepared by rf-magnetron sputtering

In order to fabricate high-brightness thin-film electroluminescent devices, the dependence of crystallinity on deposition conditions of the ZnS:Tb,F thin films deposited by rf-magnetron sputtering system have been studied. The optimal deposition conditions to get the best crystallinity are obtained as rf power density of 4.39 W/cm2, substrate temperature 150 °C, and post-anneal at 550 °C for 1 h. The (111) plane spacing and lattice constant are 3.1238 and 5.411 Å, respectively. The green electroluminescent devices with the structure of glass/indium-tin-oxide/SiO2/HfO2/ZnS:Tb,F/HfO2/SiO2/Al have the highest brightness and luminous efficiency hη of 830 cd/m2 and 0.8 lm/W, respectively, under 1 kHz sinusoidal wave voltage excitation and the Commission Internationale de l’Eclairage chromaticity is x=0.3096, y=0.5998, respectively.