Pulsed-laser deposition of ZnS and SrS for ACTFEL and field-emission displays

High-quality luminescent thin films of manganese-doped zinc sulphide (ZnS:Mn) and strontium sulphide (SrS) with excellent stoichiometry have been grown by pulsed-laser deposition (PLD). The crystallinity, stoichiometry, and cathodoluminescence have been investigated for films deposited onto two different substrate types under different deposition conditions. Furthermore, the importance of post-deposition annealing has been studied. PLD ZnS:Mn thin films show increased cathodoluminescence (CL) when compared to sputtered thin films, peaking at 585 nm. SrS thin films grown at 450°C onto tin-doped indium oxide (ITO) coated glass substrates show very good crystallinity, with a preferred orientation along the (200) axis. Cerium-doped strontium sulphide (SrS:Ce) gives strong blue CL output at 400 nm. The films are stoichiometric and it has been shown that the stoichiometry is controllable by varying the deposition parameters.