Table of Contents Entry This review covers energy harvesting technologies associated with piezoelectric materials along with the sub-classes of pyroelectrics and ferroelectrics. These properties are often present in the same material, providing the intriguing prospect of a material that can harvest energy from multiple sources including vibration, thermal fluctuations and light.

The pre‐existing Fermi level alignment between ZnO and CuSCN semiconductors gives rise to the two key elements needed for a self‐powered, binary‐response UV‐ sensor: photovoltaic behavior and low turn‐on bias. Nanosecond response times, self‐powered performance, and long‐term stability, coupled with scalable, inexpensive fabrication on the nanoscale, offer currently unmatched progression towards self‐sufficient nanoscale systems.

BaTiO 3 is used as a target catalyst to probe the influence of ferroelectricity on the decolorization of a typical dye moleculeRhodamine Bunder simulated solar light. We show that there is a 3-fold increase in the decolorization rate using BaTiO 3 with a high tetragonal content compared to predominantly cubic material. This is ascribed to the ferroelectricity of the tetragonal phase. The influence of ferroelectricity ensures a tightly bound layer of dye molecule and also acts to separate the photoexcited carriers due to the internal space charge layer. Both of these features act to enhance the catalytic performance. When nanostructured Ag is photochemically deposited on the surface of the BaTiO 3 , we find a further increase in the reaction rate that gives complete decolorization of the dye in around 45 min.

No abstract

Colloidal semiconductor nanocrystals are promising luminophores for creating a new generation of electroluminescence devices. Research on semiconductor nanocrystal based light-emitting diodes (LEDs) has made remarkable advances in just one decade: the external quantum efficiency has improved by over two orders of magnitude and highly saturated color emission is now the norm. Although the device efficiencies are still more than an order of magnitude lower than those of the purely organic LEDs there are potential advantages associated with nanocrystal-based devices, such as a spectrally pure emission color, which will certainly merit future research. Further developments of nanocrystal-based LEDs will be improving material stability, understanding and controlling chemical and physical phenomena at the interfaces, and optimizing charge injection and charge transport.

Atomic polarization in ferroelectric compounds is manipulated to control local electronic structure and influence chemical reactivity. Ferroelectric domains are patterned with electron beams or with probe tips, and electron exchange reactions occur preferentially on positive or negative domains. Using photo reduction from aqueous solution, metal nanoparticles are produced in predefined locations on an oxide substrate. Subsequently, organic molecules are reacted selectively to the particles. The process can be repeated to develop complex structures consisting of nanosized elements of semiconductors, metals, or functional organic molecules.

New hybrid materials consisting of ZnO nanorods sensitized with three different biomass-derived carbon quantum dots (CQDs) were synthesized, characterized, and used for the first time to build solid-state nanostructured solar cells. The performance of the devices was dependent on the functional groups found on the CQDs. The highest efficiency was obtained using a layer-by-layer coating of two different types of CQDs.

No abstract