Dual electrically and thermally responsive broadband reflectors based on polymer network stabilized chiral nematic liquid crystals: the role of crosslink density.

A broadband reflector based on a polymer stabilized chiral nematic liquid crystal has been fabricated. The reflection bandwidth can be manually controlled by an electric field and autonomously by temperature.

Electrically switchable polymer stabilised broadband infrared reflectors and their potential as smart windows for energy saving in buildings.

Electrically switchable broadband infrared reflectors that are relatively transparent in the visible region have been fabricated using polymer stabilised cholesteric liquid crystals. The IR reflectors can change their reflection/transmission properties by applying a voltage in response to changes in environmental conditions. Simulations predict that a significant amount of energy can be saved on heating, cooling and lighting of buildings in places such as Madrid by using this switchable IR reflector.

Enhanced Amplified Spontaneous Emission in Perovskites Using a Flexible Cholesteric Liquid Crystal Reflector.

Organic-inorganic perovskites are highly promising solar cell materials with laboratory-based power conversion efficiencies already matching those of established thin film technologies. Their exceptional photovoltaic performance is in part attributed to the presence of efficient radiative recombination pathways, thereby opening up the possibility of efficient light-emitting devices. Here, we demonstrate optically pumped amplified spontaneous emission (ASE) at 780 nm from a 50 nm-thick film of CH3NH3PbI3 perovskite that is sandwiched within a cavity composed of a thin-film (∼7 μm) cholesteric liquid crystal (CLC) reflector and a metal back-reflector.

Effect of temperature on symmetry breaking excited state charge separation: restoration of symmetry at elevated temperature.

With an increase in temperature, an unprecedented restoration of symmetry in the symmetry breaking excited state charge transfer is observed in a geminal pair of near-orthogonally connected perylenimide dimers. Such restoration of symmetry could be attributed to the interchromophoric planarization and/or loss of solvation asymmetry at elevated temperature resulting in enhanced fluorescence quantum yield.