Optically and Electrically Controlled Circularly Polarized Emission from Cholesteric Liquid Crystal Materials Doped with Semiconductor Quantum Dots

Abstract

Novel types of electro- and photoactive quantum dot-doped cholesteric materials have been engineered. UV-irradiation or electric field application allows one to control the degree of circular polarization and intensity of fluorescence emission by prepared quantum dot-doped liquid crystal films.

Light polarization states of a cholesteric liquid crystal probed with optical ellipsometry

“…We estimated the pitch as p = 0.43 lm by using the relation above and considering HTP = +6.67 lm À1 for the chiral dopant CB15. When the Ch-sample was sandwiched between two glass-slides as described above the planar texture (or Grandjen) was observed under POM at 24.1°C, this texture is quite stable [6][7][8][9] and we observed that the optical properties are still stable over more than one year. In Fig.…”

“…On the other hand, when the temperature increases, the springs are compressed and the reflected wavelengths are shorter (hypsochromic shift) [4,5]. Furthermore, these materials feature sufficient optical stability for many applications [6][7][8][9]. The main applications of chiral macrostructures include: bistable cholesteric reflective displays [10][11][12][13][14], optical filter for circularly polarized light in LCDs [15], electrically switchable mirrors [16], chiral pharmaceutical resolution [17], and photonic band gap materials [18,19].…”

Technology for Creation and Detailed Analysis of Polymer Composites with Uniform Distribution of Quantum Dots and Liquid Crystals

“…Our research team was actively involved in the development [13][14][15][17][18][19][20][21][22] of methods for characterization [16] of devices with similar structure. In the course of the study, some possibilities of photo-and electro-manipulation by circularly polarized fluorescence were demonstrated and a new approach to the introduction of high concentrations of QDs in a cholesteric liquid crystal (LC) matrix was developed.…”

Correlative Microscopy: A Potent Tool for Biomedicine

“…Examples of the implementation of such a system are presented in [6][7][8]. In particular, a correlation was established in [7] between the 3-D distribution of nanosized fluorescent nanocrystals (quantum dots) in the liquid crystal matrix and the local degree of fluorescence depolarization in the local nanoscale regions of the nanomaterial LC matrix.…”