J. S. Roy

Enhanced photoluminescence of antiferroelectric liquid crystals doped with sodium titanate nanoparticles

We have observed the enhancement in photoluminescence (PL) intensity of the antiferroelectric liquid crystals (AFLC) doped with Sodium titanate nanoparticles (NPs). The enhancement in PL intensity of AFLC strongly depends on the doping concentration of NPs. The Sodium titanate NPs were prepared such that the emission from NPs together with AFLC molecules gives enhanced PL intensity. On the other hand, smectic CA* phase of AFLC provides strong light scattering and hence incident photons get scattered to excite more NPs and give enhanced PL counts. We have also observed the shift in emission energy band of AFLC doped with NPs.

Optical characterization of ZnS coated CdS nanorods embedded in liquid crystals

The photoluminescence (PL) emission intensity of ZnS coated CdS nanorods, represented by CdS/ZnS system, have been enhanced in presence of liquid crystals (LC) and the enhancement strongly depends on concentration of LC. The highly light scattering liquid crystalline phase causes the enhancement in PL intensity. It is also observed that the PL intensity of CdS nanorods enhances with the coating of ZnS material. This enhancement in PL intensity is ascribed by the fact that the high optical band gap ZnS material prevents the tunneling of the charge carriers from the core CdS nanorods and passivated nonradiative recombination sites which are existed on the core surfaces. Finally, 5 fold enhancements in PL intensity of CdS nanorods have been observed by coating with ZnS material and then embedding in LC. We have also observed the red shift in emission energy band of CdS/ZnS system embedded in LC. This study will provide a possible way to develop smart optoelectronics devices.