Organic–inorganic hybrid materials do not represent only a creative alternative to design new materials and compounds for academic research, but their improved or unusual features allow the development of innovative industrial applications. Nowadays, most of the hybrid materials that have already entered the market are synthesised and processed by using conventional soft chemistry based routes developed in the eighties. These processes are based on: a) the copolymerisation of functional organosilanes, macromonomers, and metal alkoxides, b) the encapsulation of organic components within sol–gel derived silica or metallic oxides, c) the organic functionalisation of nanofillers, nanoclays or other compounds with lamellar structures, etc. The chemical strategies (self-assembly, nanobuilding block approaches, hybrid MOF (Metal Organic Frameworks), integrative synthesis, coupled processes, bio-inspired strategies, etc.) offered nowadays by academic research allow, through an intelligent tuned coding, the development of a new vectorial chemistry, able to direct the assembling of a large variety of structurally well defined nano-objects into complex hybrid architectures hierarchically organised in terms of structure and functions. Looking to the future, there is no doubt that these new generations of hybrid materials, born from the very fruitful activities in this research field, will open a land of promising applications in many areas: optics, electronics, ionics, mechanics, energy, environment, biology, medicine for example as membranes and separation devices, functional smart coatings, fuel and solar cells, catalysts, sensors, etc.

Applications of hybrid organic–inorganic nanocomposites

Increasing demand for raw materials means that alternatives to indium-tin oxide are desired for optically transparent electrode applications. Carbon nanotube, metal nanowire networks and regular metal grids have been investigated as possible options. In this review, these materials and recently rediscovered graphene are compared with the usual transparent conductive oxides.

Past achievements and future challenges in the development of optically transparent electrodes

Thermoelectric generators (TEGs) transform a heat flow into electricity. Thermoelectric materials are being investigated for electricity production from waste heat (co-generation) and natural heat sources. For temperatures below 200 °C, the best commercially available inorganic semiconductors are bismuth telluride (Bi(2)Te(3))-based alloys, which possess a figure of merit ZT close to one. Most of the recently discovered thermoelectric materials with ZT>2 exhibit one common property, namely their low lattice thermal conductivities. Nevertheless, a high ZT value is not enough to create a viable technology platform for energy harvesting. To generate electricity from large volumes of warm fluids, heat exchangers must be functionalized with TEGs. This requires thermoelectric materials that are readily synthesized, air stable, environmentally friendly and solution processable to create patterns on large areas. Here we show that conducting polymers might be capable of meeting these demands. The accurate control of the oxidation level in poly(3,4-ethylenedioxythiophene) (PEDOT) combined with its low intrinsic thermal conductivity (λ=0.37 W m(-1) K(-1)) yields a ZT=0.25 at room temperature that approaches the values required for efficient devices.

Optimization of the thermoelectric figure of merit in the conducting polymer poly(3,4-ethylenedioxythiophene)

Highly conductive poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) films as stand-alone electrodes for organic solar cells have been optimized using a solvent post-treatment method. The treated PEDOT:PSS films show enhanced conductivities up to 1418 S cm−1, accompanied by structural and chemical changes. The effect of the solvent treatment on PEDOT:PSS has been investigated in detail and is shown to cause a reduction of insulating PSS in the conductive polymer layer. Using these optimized electrodes, ITO-free, small molecule organic solar cells with a zinc phthalocyanine (ZnPc):fullerene C60 bulk heterojunction have been produced on glass and PET substrates. The system was further improved by pre-heating the PEDOT:PSS electrodes, which enhanced the power conversion efficiency to the values obtained for solar cells on ITO electrodes. The results show that optimized PEDOT:PSS with solvent and thermal post-treatment can be a very promising electrode material for highly efficient flexible ITO-free organic solar cells.

Highly Conductive PEDOT:PSS Electrode with Optimized Solvent and Thermal Post-Treatment for ITO-Free Organic Solar Cells

On the mechanism of conductivity enhancement in poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) film through solvent treatment

An overview of one of the most successful conducting polymers, poly(3,4-ethylenedioxythiophene) (PEDT) and its derivatives, is presented, detailing its early development, the synthesis of numerous hybrid and derivative materials, along with a description of the broad array of properties accessible and a description of a set of the more prominent applications in which they can be utilized. Synthetic flexibility and facility is the key to the many new 3,4-ethylenedioxythiophene- (EDT-) based monomers, oligomers, and (co) polymers. These (co) polymers provide highly conducting and especially stable doped states, a range of optical properties with electronic bandgaps varying across the entire visible spectrum, and enhanced redox properties, making them useful for numerous electrochemical devices. Present and future applications for PEDT that are discussed include static charge dissipation films and electrode materials in solid electrolyte capacitors.

Poly(3,4‐ethylenedioxythiophene) and Its Derivatives: Past, Present, and Future

Transparent functional layers of conductive polymers, their production and their use in optical constructions.

Functional layers for optical uses based on polythiophenes

The invention relates to transparent functional layers made of conductive polymers, preferably based on polythiophenes, to the production thereof and to their use in optical structures.

Functional layers for optical applications based on polythiophenes

Die Erfindung betrifft transparente Funktionsschichten aus leitfahigen Polymeren, bevorzugt auf Basis von Polythiophenen, deren Herstellung und deren Verwendung in optischen Aufbauten.

F. Jonas

Papers

Poly(3,4‐ethylenedioxythiophene) and Its Derivatives: Past, Present, and Future

Functional layers for optical uses based on polythiophenes

Functional layers for optical applications based on polythiophenes

Funktionsschichten für optische Anwendungen auf Basis von Polythiophenen