CdSe quantum dot-dispersed DOBAMBC: an electro-optical study

Abstract

Cadmium selenide quantum dot (CdSe QD) has been used as a dopant in ferroelectric liquid crystal (FLC) 2-methylbutyl 4-(4-decyloxybenzylideneamino) cinnamate (DOBAMBC). Effect of CdSe QD in DOBAMBC on its different electro-optical (E-O) properties has been studied in the SmC* phase. The optical micrographs recorded for the pure and composite material are showing good dispersion of QDs in the FLC matrix. Micrographs of unaligned sample cell revealed that CdSe QDs induce homeotropic alignment of FLC molecules. An appreciable change in the value of E-O parameters like tilt angle, spontaneous polarisation and response time with shifting of SmA–SmC* phase transition temperature has been observed for CdSe QD–DOBAMBC composite. The observed properties of composite system have been discussed on the basis of surface properties of QDs in FLC system.

Keywords:

• ferroelectric liquid crystal
• quantum dots
• composite system
• electro-optical properties

Acknowledgements

Author S. K. Gupta is thankful to Council of Scientific and Industrial Research, New Delhi, India, for the grant of SRF fellowship no. 09/107/(0337)/2010-EMR-I. All the authors are thankful to ISRO-RESPOND for the grant in the form of project.