Quantum dot dispersion in nematic liquid crystal

Optical and electrical properties of quantum dots can be~significantly altered~by aligning the dots in a linear chain. ~Dispersing quantum dots in liquid crystals can lead to the formation of linear chains due to the partial ordering of the liquid crystal molecules. ~Typically, this results in a red shift in the emission spectrum of the dots as the induced order leads to enhanced~dipolar interactions, resulting in electronically coupled states.~Dispersions of quantum dots are studied as a function of the concentration, size, and shape of the dots in a nematic rod-like liquid crystal material. ~The quantum dots~are seen to aggregate if the concentration of the dots~is too high, leading to little correlation between the quantum dot dispersion and liquid crystal texture. ~In decreasing the quantum dot concentration the aggregates lessen in size and are more uniformly distributed within the liquid crystal. ~Spherical, rod-like, and disc-like quantum dots with emission peaks ranging from 490 nm to 640 nm were studied using polarized optical microscopy and scanning microscopy photoluminescence measurements.