Synthesis and characterization of some ZnS-based thin film phosphors for electroluminescent device applications

ZnS:Mn, ZnGaS:Mn and ZnS:CuCl2 phosphor thin films for alternating-current thin-film electroluminescent (ACTFEL) devices were prepared by thermal evap oration from two and three sources, respectively. Films are polycrystalline , strongly oriented and stoichiometric or nearly stoichiometric with high o ptical transmission in the visible part of the spectrum. The band gap of Zn S:Mn, ZnGaS:Mn and ZnS:CnCl(2) Alms was found to be 3.63, 3.86 and 3.56 eV, respectively. The sheet resistance of the ZnS:Mn and ZnGaS:Mn films was gr eater than 100 Mn. The resistivity of ZnS:CuCl2 films was between 1.5-80 Om ega cm. Photoluminescent (PL) and electroluminescent (EL) characteristics w ere also studied. The results indicate that after the optimization the inve stigated phosphor thin films will be suitable for ACTFEL device application s. (C) 2000 Elsevier Science S.A. All rights reserved.