Physico-Chemical nanomaterials science
Anisotropy of optical properties of liquid crystalline self- assembled InP/ZnS nanocrystals
Parzyszek S., Pociecha D., Lewandowski W.
University of Warsaw, Faculty of Chemistry, Pasteura 1 St., 02-093 Warsaw, Poland. 
E-mail: sparzyszek@chem.uw.edu.pl

Increasing number of possible applications for semiconductor quantum dots (QDs) and their intrinsic optical properties cause unceasing interest of researchers.  In this respect, a number of wet chemical methods were developed to obtain QDs with precisely controlled morphology-, size- and shape-dependent optoelectronic properties. However parameters central to the operation of QD-based devices, such as the structural stability, carrier mobility, fluorescence intensity, can also be controlled by managing distant-dependent, collective interactions of QDs. Predictively reconfigurable arrangement of nanoparticles can represent another expedient strategy for controlling properties of QD thin films. One approach to achive this goal is forming dynamically switchable self- assemblies of QDs coated with promesogenic ligands and short alkyl thiols.
The aim of this work was to obtain novel semiconductor composites with additionally dynamically switchable and fully controlled structure properties. For this purpose monodisperse, heavy- metal free InP/ZnS QDs were synthesized. In next step organic coating of QDs was modified. Oleylamine as primary ligand was exchanged for mixture of 1-dodecanethiol and promesogenic ligand. This hybrid nanomaterial exhibits ability to form long-range ordered, reversibly reconfigurable structures in unary systems As prepared materials were examinated using TEM, SAXS (Small Angle X-Ray Scattering), UV-VIS and fluorescence spectroscopy.

The research is conducted under Reinforce project carried out within the First Team program of the Foundation for Polish Science co-financed by the European Union under the European Regional Development Fund