41-2:Invited Paper: Quantum Dots and Aligned Quantum Rods for Polarized LC Backlights

Abstract

A backlight that emits linearly polarized light would make it possible to increase the transmission through the first polarizer by a factor two. We used quantum rods that have a CdSe core that emits partially polarized yellowish green light (around 570 nm) and a CdS bulk that absorbs blue. The quantum rods can be aligned with their long axis parallel to an applied electric field with sufficient amplitude. The resulting layer emits linearly polarized light with a high degree of polarization. Such a layer can be used in different backlight configurations. Author KeywordsPolarized backlight; quantum dots; quantum rods; electric field alignment; backlight architectures.

Quantum‐Dot and Quantum‐Rod Displays – the Next Big Wave

“…Ghent University showed that QRs can be aligned with their long axis parallel to an applied electric field with sufficient amplitude by using the dip-coating technique. 18 A substrate with ITO electrodes in a finger pattern was slowly pulled out of a suspension with CdSe/CdS quantum rods while an ac electric field was applied. The Ghent researchers demonstrated that this procedure makes it possible to align and fix the QRs in the desired orientation.…”

“…Images from Ghent University include (a) top left: the fluorescence of oriented QRs under a polarizing microscope; top right: the dependency of the PL intensity on the azimuth angle of the polarizer; and bottom: the fluorescence microscopy of a particular region on the substrate with oriented QRs with the polarizer parallel (left) and perpendicular (right) to the applied electric field 18 . (b) Hong Kong University of Science and Technology's image shows the process flow of QR‐dispersed aligned LCP films 19 …”

P‐116: Field Assisted Unidirectional Alignment of Quantum‐Rods with Polarized Light Emission

“…However, the vigorous task of using these QRs for the desired purpose is to align them in a perfectly unidirectional array so as to get higher polarized light emission. Several approaches have been projected such as electric field-assisted assembly [5], using photo-alignment layer [6], arrangement in liquid crystal defects [7], solvent-based assembly [8] and embedding the QRs in nanofiber sheets using electrospinning [9].…”

18‐3: Polarized Emission from Stretch‐Aligned Perovskite Nanorods‐Polymer Composites with High Stability

“…LCDs operate with polarized light and therefore a linear polarizer is placed between the backlight and the LC panel, which absorbs typically 50% of the light. A backlight with intrinsic polarization is thus preferred to improve the overall optical efficiency [3].…”