Competing Mechanisms Determine Oxygen Redox in Doped Ni-Mn Based Layered Oxides for Na-Ion Batteries.

Cation doping is an effective strategy for improving the cyclability of layered oxide cathode materials through suppression of phase transitions in the high voltage region. In this study, Mg and Sc are chosen as dopants in P2-NaNiMnO, and both have found to positively impact the cycling stability, but influence the high voltage regime in different ways. Through a combination of synchrotron-based methods and theoretical calculations it is shown that it is more than just suppression of the P2 to O2 phase transition that is critical for promoting the favorable properties, and that the interplay between Ni and O activity is also a critical aspect that dictates the performance.

Morphological and Surface-State Challenges in Ge Nanoparticle Applications.

The intrinsic properties of Ge in tandem with advances in its nanostructuring have resulted in its increased attention in a variety of fields as an alternative to traditional group 12-14 and 14-16 nanoparticles (NPs). The small band gap and size-dependent development of the optical properties in tandem with their good charge transport properties make Ge NPs a suitable material for optoelectronic devices. The low toxicity of Ge, together with its IR photoluminescence (PL) that overlaps with desirable biological optical windows used for tissue imaging, allows the exploitation of these materials in the field of bioimaging and as drug carriers.

Crystallinity and Size Control of Colloidal Germanium Nanoparticles from Organogermanium Halide Reagents.

Germanium (Ge) nanoparticles are gaining increasing interest due to their properties that arise in the quantum confinement regime, such as the development of the band structure with changing size. While promising materials, significant challenges still exist related to the development of synthetic schemes allowing for good control over size and morphology in a single step. Herein, we investigate a synthetic method that combines sulfur and primary amines to promote the reduction of organometallic Ge(IV) precursors to form Ge nanoparticles at relatively low temperatures (300 °C).

End-Functionalized Semiconducting Polymers as Reagents in the Synthesis of Hybrid II-VI Nanoparticles.

The functionalization of II-VI nanocrystals with semiconducting polymers is of fundamental interest for lightweight, solution-processed optoelectronics. The direct surface functionalization of nanocrystals is useful for facilitating charge transfer across the donor/acceptor interface, in addition to promoting good mixing properties and thereby helping prevent nanoparticle aggregation. In this work, we develop a new method for the direct attachment of semiconducting polymers to II-VI inorganic nanocrystals, where the polymer plays a dual role, acting as both the desired capping agent and a chalcogenide monomer during synthesis.

Synthesis of Ligand-free CdS Nanoparticles within a Sulfur Copolymer Matrix.

Aliphatic ligands are typically used during the synthesis of nanoparticles to help mediate their growth in addition to operating as high-temperature solvents. These coordinating ligands help solubilize and stabilize the nanoparticles while in solution, and can influence the resulting size and reactivity of the nanoparticles during their formation. Despite the ubiquity of using ligands during synthesis, the presence of aliphatic ligands on the nanoparticle surface can result in a number of problems during the end use of the nanoparticles, necessitating further ligand stripping or ligand exchange procedures.

Correction: The future of organic photovoltaics.

Correction for 'The future of organic photovoltaics' by Katherine A. Mazzio et al., Chem.

Sulfur copolymer for the direct synthesis of ligand-free CdS nanoparticles.

Organic coordinating ligands are ubiquitously used to solubilize, stabilize and functionalize colloidal nanoparticles. Aliphatic organic ligands are typically used to control size during the nanoparticle growth period and are used as a high boiling point solvent for solution-based synthesis procedures. However, these aliphatic ligands are typically not well suited for the end use of the nanoparticles, so additional ligand exchange or ligand stripping procedures must be implemented after the nanoparticle synthesis.

The future of organic photovoltaics.

Increasing global demand for energy, along with dwindling fossil fuel resources and a better understanding of the hidden costs associated with these energy sources, have spurred substantial political, academic, and industrial interest in alternative energy resources. Photovoltaics based on organic semiconductors have emerged as promising low-cost alternatives for electricity generation that relies on sunlight. In this tutorial review we discuss the relevance of these organic photovoltaics beginning with some of the economic drivers for these technologies.

A one pot organic/CdSe nanoparticle hybrid material synthesis with in situ π-conjugated ligand functionalization.

A one pot method for organic/colloidal CdSe nanoparticle hybrid material synthesis is presented. Relative to traditional ligand exchange processes, these materials require smaller amounts of the desired capping ligand, shorter syntheses and fewer processing steps, while maintaining nanoparticle morphology.

Surface-initiated synthesis of poly(3-methylthiophene) from indium tin oxide and its electrochemical properties.

Poly(3-methylthiophene) (P3MT) was synthesized directly from indium tin oxide (ITO) electrodes modified with a phosphonic acid initiator, using Kumada catalyst transfer polymerization (KCTP). This work represents the first time that polymer thickness has been controlled in a surface initiated KCTP reaction, highlighting the utility of KCTP in achieving controlled polymerizations. Polymer film thicknesses were regulated by the variation of the solution monomer concentration and ranged from 30 to 265 nm.

Oligoselenophene derivatives functionalized with a diketopyrrolopyrrole core for molecular bulk heterojunction solar cells.

Solution-processable oligoselenophenes functionalized with diketopyrrolopyrrole cores have been synthesized for use as the donor material in bulk heterojunction solar cells. The optical absorption of these materials extends to the edge of the visible spectrum. Power conversion efficiencies of 1.