14.5: Invited Paper: Novel, Flexible AC Electroluminescent Lamps for Innovative Display Applications

Abstract

Novel, flexible ACEL lamps have been developed for innovative display applications. These lamps contain a single emissive layer comprising of ACEL phosphor, a binder, ferroelectric nanoparticles and optional dye. This architecture reduces fabrication costs and enables high luminances (ca. 200 cd/m2) to be achieved at 110 V and 400 Hz.

Materials for Powder-Based AC-Electroluminescence

“…However, in principle, a thick-film AC-EL emissive system does need only one single layer, provided the total dielectric properties are still tolerable [63]. To this end, suitable binders need to incorporate the dielectric function, and phosphor particles need to be as small as possible.…”

19.6L: Late‐News Paper: How to Fabricate Much Brighter AC Electroluminescent Lamps: Optimizing the Alignment of the Emitting ZnS:Cu Phosphor Particles to the AC Field

“…Thus the panels are operating well below the maximum potential if all the crystals were aligned with the field. As such panels commonly have high luminances (ca 200 cd/m 2 ) at 110 V and 400 Hz [2][3][4], then if crystal alignment was achieved one could expect luminances of almost 400 cd/m 2 without other factors that may also increase performance such as highly reflecting back electrodes. We have previously found that using reflective back electrodes with single binder layers between the electrodes it is possible to achieve 320 cd/m 2 .…”

“….It is now possible to fabricate such panels with only one layer between the electrodes making the panels highly flexible, in such devices the layer contains a binder the ACEL phosphor powder particles and the dielectric particles [3]. Modern uses of this technology include large area flexible ACEL panels for innovative display applications [4]. Using technology we have developed and reported previously it is possible to fabricate panels that have high luminances (ca 200 cd/m 2 ) at 110 V and 400 Hz [2][3][4].…”

“…Modern uses of this technology include large area flexible ACEL panels for innovative display applications [4]. Using technology we have developed and reported previously it is possible to fabricate panels that have high luminances (ca 200 cd/m 2 ) at 110 V and 400 Hz [2][3][4]. During the course of a long ongoing research program on ACEL we have seen that about one third of the powder particles in the active panels are either very dim or emit no light at all of the remaining two thirds the emission varies from full brightness to more average brightness.…”

Patterning of Aluminium thin film on polyethylene terephthalate by multi-beam picosecond laser

“…Aluminium on PET has recently been identified as a low cost replacement for printed silver back-electrodes in AC electroluminescent displays (ACEL) which have a number of niche applications, such as back-lights for instruments in cars, aeroplanes, mobile phones, illuminated displays for advertising and safety lights [11]. Their advantages are that they provide a distributed, uniform light sources, they can be made very thin (o 60 mm) and thus flexible and robust.…”