This paper details an investigation into the deposition by RF magnetron sputtering of thin film phosphors specifically for use in laterally emitting thin film electroluminescent (EL) devices. The work presented here is concerned with the use of co-sputtering to optimise luminous efficiency and the use of transient (decay time) measurements to quantify the luminescent quality of the films. Thin films of phosphor were deposited by radio frequency RF magnetron sputtering in a custom built four electrode cluster deposition system. 800 nm films of ZnS:Mn were simultaneously cosputtered from ZnS and ZnS:Mn(l wt.%) solid targets. The thin films were deposited at different manganese concentrations by varying the RF power applied to each target.The films were deposited directly onto 100 mm diameter (100) n-type silicon substrates, or onto a layer of 300 nm of Y 2 03to fabricate electroluminescent test devices. Luminescence was characterised via photoluminescent excitation using a 337 nm pulsed N2 laser, with the PL optimum obtained at 0.38 ZnS:Mn power ratio.

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Sb doped SnO 2 has been formulated and inkjet printed onto borosilicate glass substrates. The resultant films have been post processed using traditional thermal annealing up to 440 o C and laser processing with a KrF excimer laser (λ = 248nm). Sheet resistance values of 700Ω/□ have been achieved with thermal annealing, whilst transparency remains >85% in the visible region. As a result of laser processing significant decreases in sheet resistance of the inkjet printed layers have been demonstrated indicating the viability of inkjet printing onto flexible substrates. The optical transmittance of the laser processed films has been shown to remain >85%. Initial measurements indicate that thermal and laser post processes reduce surface roughness.

The temperature sensitive nature of the substrates used in the flexible displays market necessitates a low temperature deposition technique for processing them. ZnS:Mn exhibiting high intensity photoluminescence and good crystallinity has been deposited onto Si wafers, glass microscope slides and polymeric substrates using a new reactive sputtering technology referred to as HiTUS. This technique enables very high deposition rates and requires no substrate heating. When incorporated as part of a complete EL device, as-deposited ZnS:Mn films are seen to exhibit stable electroluminescence on Si, glass and planarised PET substrate materials. Post annealing of the devices on Si and glass at temperatures of up to 600 °C show that the HiTUS films perform better than equivalent ZnS:Mn films deposited using RF magnetron sputtering.Copyright line will be provided by the publisher 1 Introduction This work compares two different sputtering techniques for the deposition of alternating current thin film electroluminescent (ACTFEL) devices. High target utilisation sputtering (HiTUS) is a new method for sputtering thin films that allows for the deposition of working electroluminescent (EL) structures with no substrate heating or post deposition annealing [1]. However, here we look at the effect of post deposition annealing HiTUS devices that have been deposited onto silicon and glass substrates with no substrate heating. Radio frequency (RF) magnetron sputtering has also been used for the fabrication of comparable devices with both substrate heating and post deposition annealing. The results of quantitative EL measurements for structures deposited using these two techniques are presented here.

This paper presents the photoluminescent (PL) and electroluminescent (EL) characteristics of ZnS:Mn deposited at room temperature using high target utilization sputtering (HiTUS). Significant improvements in PL intensity are seen when ZnS:Mn is deposited using HiTUS instead of conventional RF magnetron sputtering. When incorporated as part of a complete EL device with yttrium oxide forming the dielectric layers and indium tin oxide used as the top contact electrode, localized laser annealing of the ZnS:Mn phosphor layer is shown to provide enhancement of the EL characteristics.