xmlui.ArtifactBrowser.SimpleSearch.filter.source:Scientific papers of the University of Pardubice. Series A, Faculty of Chemical Technology. 19/2013
ISSN:1211-5541
Abstract:
In printing industry it is an important step to create more interactive designs to
attract the customers. One of them is the utilization of electroluminescence. The
properties of an electroluminescent device depend on the panel's structure, used
materials, driving voltage and frequency. In this paper, an all printed
electroluminescent panel is presented with different layer orders or number of
layers. The panels' structures differ in the position and thickness of the dielectric
layer. These different structures are causing changes in threshold voltage, highest
obtainable luminance and durability of the panel. The behaviour of the panels and
crystals of the active layer was inspected via spectrophotometry and optical
microscopy in the range of voltages from 10 to 120 V at frequencies of 50 and
500 Hz driven by an AC power source. The results show that the panel structure
with a single dielectric layer from only one side of the active layer, independently
on the position (in front of or behind the active layer) has the highest luminance.
It was revealed that the best durability is achieved with a double dielectric layer
from both sides of the active layer. Occurrence of sparking is not acceptable, and thus as the most compliant panel structure is the panel with one dielectric layer
from both sides of the active layer with luminance of more than 20 cd m–2. The
heat arising from the sheet resistance of indium tin oxide showed a slight red shift
in the emission spectra. A test on a ceramic heating table revealed that the shift
is caused by heat.
