For the growth of Electroluminescent (EL) device market, the attention of many
researchers is centered on improving the properties such as brightness, power consumption, device
reliability, etc. The powder EL device is one of solutions for the easy mass production, the
simplification of structure, and low cost. Although the powder process is the solution, that has the
problem with the poor brightness than the film process. So, we focused on increasing the brightness
of powder EL device. The emissive layer was made up the composites adding metal oxide
nanopowder such as TiO2 and ZnO to powder phosphors. As the data of previous researcher, the TiO2
and ZnO had the different dominating traps by photovoltage measure, that is, TiO2 show hole traps,
ZnO show electron traps [1]. The brightness of powder EL device proportions to the high electricfield
formation. The TiO2 or ZnO in the powder phosphor composite can help the emission that may be
advantageous to form high electricfield at low voltage. The EL devices with green ZnS phosphor
were fabricated using spin coating method. The effect of TiO2 and ZnO on the luminescent property
of EL device was investigated. The brightness was obtained as applied driving voltage at 400 Hz and
frequency variation at 50 V.
Cover Feature: Characterization of Phosphoranes Obtained by the Spontaneous Carbonyl‐Catalyzed Phosphorylation of Monosaccharides and Polyols in Aqueous Media (ChemBioChem 4/2020)