Liquid crystal cells with built-in CdSe nanotubes for chromogenic smart emission devices

Abstract

A simple and general approach for controlling optical anisotropy of nanostructured semiconductors is reported. Our design involves the fabrication of liquid crystal devices with built-in semiconductor nanotubes. Quite interestingly, it is found that semiconductor nanotubes can be well aligned along the orientation of liquid crystals molecules automatically, resulting in a very large emission anisotropy with the degree of polarization up to 72%. This intriguing result manifests a way to obtain well aligned semiconductor nanotubes and the emission anisotropy can be easily manipulated by an external bias. The ability to well control the emission anisotropy should open up new opportunities for nanostructured semiconductors, including optical filters, polarized light emitting diodes, flat panel displays, and many other chromogenic smart devices.

Room-temperature nanolaser from CdSe nanotubes embedded in anodic aluminum oxide nanocavity arrays

“…After repeating this coating process for desired coating thickness t ͑=b − a͒, the CdSe thin-ring layer would form along the inner surfaces of AAO pores. 9 In order to check the quality of the coated thin layer, we dissolved the AAO template by 1M NaOH ͑aq͒ to obtain the CdSe thin-ring layer.…”

Detailed mechanism for the orthogonal polarization switching of gold nanorod plasmons

“…An interesting strategy to modulate the LSPR of plasmonic NPs is to use liquid crystals (LCs), [25][26][27][28][29][30][31][32][33][34][35][36][37] as their refractive index is anisotropic and can be changed through the alignment of the LC molecules. The average alignment direction of the LC molecules for a nematic LC is known as the nematic director, and its orientation is controllable by an externally applied voltage.…”

“…The average alignment direction of the LC molecules for a nematic LC is known as the nematic director, and its orientation is controllable by an externally applied voltage. [25][26][27][28][29][30][31][32][33][34][35] Refractive index differences between the extraordinary and ordinary axes (parallel and perpendicular to the nematic director) for thermotropic LCs can be as large as Dn = 0.2 and should theoretically shift the LSPR up to 100 nm for gold nanorods (AuNRs) or NP dimers surrounded by a LC medium. [38][39][40] Instead, only moderate LSPR shifts of 10-20 nm have been observed for LC-based modulation of plasmonic NPs.…”

Effects of Nanoscaled Tin-Doped Indium Oxide on Liquid Crystals against Electrostatic Discharge

“…So far the subjects have included various kinds of materials such as metallic Ag-or Pd-nanoparticles [1,2], CNTs [3,4,[11][12][13], diamond particles [14], semiconductive nanotubes [15], cage-like polymeric molecules such as polyhedral oligomeric silsesquioxanes (POSS) [16,17], and ferroelectric particles [5,18]. By using these nanoparticle candidates, newly found texture, switching behavior, or enhanced electro-optical response for the modified LC can be achieved.…”