Luminescent Down‐Conversion Semiconductor Quantum Dots and Aligned Quantum Rods for Liquid Crystal Displays

Abstract

Herein, emerging applications of luminescent semiconductor nanocrystals are addressed, such as quantum dots and quantum rods as down‐conversion materials used in liquid crystal displays (LCD). Their precisely tunable emission wavelengths and narrow emission bandwidths offer high color purity resulting in a wide color gamut with vivid colors for LCDs. Anisotropic materials, such as quantum rods, have the additional advantage of polarized emission, which can bring a significant improvement to the efficiency of LCD displays. The basic optical properties of these nanomaterials are considered, with a focus on quantum rods, and the challenges and progress in their assembly are discussed. Different techniques for quantum rod alignment are introduced such as shear‐oriented, electric field and magnetic field assisted assembly, mechanical rubbing, stretching, and electrospinning. The photoalignment approach allows for an easy arrangement of quantum rods in‐plane, and the implications of this method to patterning are considered. Different configurations of LCDs utilizing semiconductor quantum dots and quantum rods as down‐conversion layers are also presented, and the potential applications that are enabled by the wide range of emerging materials are highlighted.

Shape-Controlled Synthesis of Copper Indium Sulfide Nanostructures: Flowers, Platelets and Spheres

“…However, unlike these examples, our CIS NPLs had the platelet length (rather than the thickness) extended along the <001> direction, corresponding to the c-axis of the wurtzite NPLs are an interesting class of 2D nanostructures, which can show a strong quantum size confinement effect in one direction (normal to the plate plane). CdSe NPLs with different numbers of layers have been extensively studied, and have showed strikingly narrow absorption and fluorescence spectra [5,7]. For the copper-based chalcogenides, some 2D nanostructures have also been reported, such as CIS hexagonal nanosheets synthesized via a cation exchange method or produced by so-called bottom-up synthesis methods [24,25].…”

“…Beside the size, the shape also has a strong influence on the electronic structure and optical properties of semiconductor nanostructures [4,5]. For example, polarized emission is a characteristic property of one-dimensional (1D) semiconductor nanorods [6], which can be used for application in displays [7]. Two-dimensional (2D) semiconductor nanoplatelets (NPLs) have also been widely developed and investigated [5,8].…”

“…Two-dimensional (2D) semiconductor nanoplatelets (NPLs) have also been widely developed and investigated [5,8]. CdSe NPLs with a low number of layers, defined with atomic precision, show very narrow absorption and fluorescence spectra [7], and polarized emission was observed as well [9]. Size-and shape-controlled syntheses of Cd-based semiconductor nanostructures has been, in general, well developed: dot-, rod-, wire-, platelet-, tetrapod-or octapod-shaped NCs have all been produced and extensively studied [10][11][12].…”

Carbon Dots as New Generation Materials for Nanothermometer: Review

“…SQDs have been extensively reviewed in terms of synthesis, physicochemical properties, luminescence, as well as their potential applications. Here, we direct the attention of the reader to these numerous remarkable reviews [42][43][44][45][46]. Compared to organic dyes, SQDs exhibit superior brightness for detection, a wider excitation profile for multiplexing, and better photostability for longterm studies.…”

Nano–Micro Dimensional Structures of Fiber‐Shaped Luminous Halide Perovskite Composites for Photonic and Optoelectronic Applications

“…Up to date, nano‐ or microdimensional fiber‐shaped composite structures were prepared using various kinds of methods including physical drawing, [ 82–84 ] electrospinning, [ 85,86 ] and microfluidic spinning. [ 87 ] Among them, electrospinning technique is one of the most facile and versatile tools to form nano‐/micron‐ sized fibers.…”