Oct 21 2005
Tunability of emission color is of great importance in the development of organic light-emitting materials and devices. Recently fluorescent organic nanoparticles have inspired growing research interests because of their variability and flexibility in materials synthesis and nanoparticle preparations as well as high potentials in the application of optoelectronic materials and devices.
Its applications could range from a simple (solid state) LED to, possibly, a flat-panel display for a television set, depending on the physical properties of the structure (such as its lifespan, temperature quenching behavior and luminescence intensity).
On the basis of their previous research work on nanoparticles from a series of pyrazoline compounds, Prof. YAO Jiannian and colleagues at the CAS Institute of Chemistry have successfully prepared 4-(dicyanomethylene)-2-methyl-6-(p-dimethyl- aminostyryl)-4H-pyran (DCM), a red emission materials widely used in EL devices, doped 1, 3, 5-triphenyl-2-pyrazoline (TPP) nanoparticles with DCM as the acceptor and TPP the donor. This work has been published in the recent issue of journal Advanced Materials.
The researchers have observed in the nanoparticles the highly efficient energy transfer dominated by the Förster resonance mechanism as well as tunable emission from blue to red dependent on the DCM doping content. The energy transfer and the red-shift of the emission of DCM caused by the aggregation of itself are supposed to be responsible for the tunable emission. The polymer films with doped nanoparticles dispersed in showing tunable emission have been prepared successfully giving an experimental demonstration of emission tuning in the practical forms.
Other than tuning emission by size, the work provides an alternative way, both facile and effective, to control the emission of organic nanoparticles by employing the doping technique and this is likely to be interesting to the researchers in the areas of optoelectronic materials and devices.