Optical Properties of a Composite System with Nematic LC and Colloids Quantum Dots

Background: Optical luminescence in a composite system with nematic LC 4- octyloxy-4’-cyanobuphenyl (8OCB) and semiconductor quantum dots CdSe/CdS and CdSe/CdS/ZnS has been synthesized by a water-organic method. Methods: Composites have been investigated by means of polarizing microscopy, dynamic light scattering, and measurements of dielectric properties in the frequency range from 20 Hz to 5 MHz. The non-radiative excitation energy transfer from the liquid crystal molecules to the quantum dot in the LC-QD composite is detected by using the luminescence spectroscopy method. Results: This effect as well as the shift of the luminescence band is owing to components’ intermolecular interaction. Conclusion: The optimal concentration of QD in a composite that enhanced luminescence intensity was detected.