Stacking architecture for collimated backlight using cylindrical lens sheet with linear light sources or edge-lit/direct-lit BLU.

Highly collimated and directional backlights are essential for realizing advanced display technologies such as autostereoscopic 3D displays. Previously reported collimated backlights, either edge-lit or direct-lit, in general still suffer unsatisfactory form factors, directivity, uniformity, or crosstalk etc. In this work, we report a simple stacking architecture for the highly collimated and uniform backlights, by combining linear light source arrays and carefully designed cylindrical lens arrays. Experiments were conducted to validate the design and simulation, using the conventional edge-lit backlight or the direct-lit mini-LED (mLED) arrays as light sources, the NiFe (stainless steel) barrier sheets, and cylindrical lens arrays fabricated by molding. Highly collimated backlights with small angular divergence of ±1.45°âˆ¼±2.61°, decent uniformity of 93-96%, and minimal larger-angle sidelobes in emission patterns were achieved with controlled divergence of the light source and optimization of lens designs. The architecture reported here provides a convenient way to convert available backlight sources into a highly collimated backlight, and the use of optically reflective barrier also helps recycle light energy and enhance the luminance. The results of this work are believed to provide a facile approach for display technologies requiring highly collimated backlights.

Donor-acceptor conjugated polymers based on multifused ladder-type arenes for organic solar cells.

Harvesting solar energy from sunlight to generate electricity is considered as one of the most important technologies to address the future sustainability of humans. Polymer solar cells (PSCs) have attracted tremendous interest and attention over the past two decades due to their potential advantage to be fabricated onto large area and light-weight flexible substrates by solution processing at a lower cost. PSCs based on the concept of bulk heterojunction (BHJ) configuration where an active layer comprises a composite of a p-type (donor) and an n-type (acceptor) material represents the most useful strategy to maximize the internal donor-acceptor interfacial area allowing for efficient charge separation. Fullerene derivatives such as [6,6]-phenyl-C61 or 71-butyric acid methyl ester (PCBM) are the ideal n-type materials ubiquitously used for BHJ solar cells. The major effort to develop photoactive materials is numerously focused on the p-type conjugated polymers which are generally synthesized by polymerization of electron-rich donor and electron-deficient acceptor monomers. Compared to the development of electron-deficient comonomers (acceptor segments), the development of electron-rich donor materials is considerably flourishing. Forced planarization by covalently fastening adjacent aromatic and heteroaromatic subunits leads to the formation of ladder-type conjugated structures which are capable of elongating effective conjugation, reducing the optical bandgap, promoting intermolecular π-π interactions and enhancing intrinsic charge mobility. In this review, we will summarize the recent progress on the development of various well-defined new ladder-type conjugated materials. These materials serve as the superb donor monomers to prepare a range of donor-acceptor semi-ladder copolymers with sufficient solution-processability for solar cell applications.

Synthesis and supramolecular assembly of pentacyclic dithienofluorene and diselenophenofluorene derivatives.

2,7-Diiodo-3,6-dibromofluorene and 2,7-dichloro-3,6-dibromofluorene have been successfully synthesized. The two key intermediates enable us to implement a regioselective Sonogashira reaction followed by intramolecular thiolate/acetylene cyclization, forming two regiospecific pentacyclic dithieno[2,3-b:7,6-b']fluorene (2,7-DTF) and dithieno[3,2-b:6,7-b']fluorene (3,6-DTF) isomeric molecules, respectively. By using a similar strategy, selenophene-based diselenopheno[2,3-b:7,6-b']fluorene (2,7-DSF) as well as diselenopheno[3,2-b:6,7-b']fluorene (3,6-DSF) were also prepared. The isomeric and sulfur/selenium effects determine the optical, electrochemical, and orbital properties. X-ray crystallography revealed that 2,7-DTF and 3,6-DTF molecules assemble into supramolecular helical structures.

Synthesis and molecular properties of tricyclic biselenophene-based derivatives with nitrogen, silicon, germanium, vinylidene, and ethylene bridges.

A new class of biselenophene-based materials including an sp(3)-silicon-bridged diselenosilole (DSS), an sp(3)-germanium-bridged diselenogermole (DSG), and an sp(3)-nitrogen-bridged diselenopyrrole (DSP) as well as an sp(2)-vinylidene-bridged dicyanodiselenofulvene (CDSF), a diacetylenediselenofulvene (ADSF), and a dioctylethylene-bridged benzodiselenophene (BDS) have been successfully synthesized and characterized. The bridging moieties play an important role in determining the optical and electrochemical properties. The six brominated derivatives are ready to construct various biselenophene-based conjugated materials with tunable properties for organic photovoltaics and field effect transistors.

Synthesis and molecular properties of four isomeric dialkylated angular-shaped naphthodithiophenes.

A new strategy to synthesize 4,9- and 5,10-dialkylated α-aNDTs as well as 4,9- and 5,10-dialkylated ß-aNDTs is described. Four isomeric precursors with different dithienyl-ene-diyne arrangements undergo base-induced double 6π-cyclization to construct the central naphthalene cores, leading to the formation of the regiospecific products. These 2,7-distannylated dialkylated aNDT-based monomers can be used for Stille cross-coupling to produce promising conjugated materials for various optoelectronic applications.

Diindenothieno[2,3-b]thiophene arene for efficient organic photovoltaics with an extra high open-circuit voltage of 1.14 ev.

We report a novel diindenothieno[2,3-b]thiophene ladder-type hexacyclic arene for constructing a donor-acceptor copolymer PDITTDTBT. A device based on PDITTDTBT:PC(71)BM exhibited a high V(oc) of 0.92 V with an impressive PCE of 5.8%, while a PDITTDTBT:DMPCBA-based device showed an extra high V(oc) of 1.14 V.

Anticholinergic poisoning from a large dose of Scopolia extract.

Scopolia extract (SE) contains hyoscyamine and scopolamine, which are both anticholinergic. It is usually used as a patent medicine to treat gastrointestinal disorders, to relieve spasmotic discomfort, or to decrease the secretion of gastric acid. Poisoning by SE presents similar symptoms and signs as other types of anticholinergic poisoning. We report a case of severe anticholinergic poisoning after accidentally drinking 8 ml of SE. The patient presented with acute delirium and was successfully treated with physostigmine.