Conducting polymers (CPs) have been extensively studied and widely applied in various organic devices. To improve the performances or extend the functions of the devices, CPs usually have to be nanostructured. Electrosynthesis provides an effective and convenient one-step approach to CP nanomaterials. The resulting materials are usually oriented on the electrode surfaces and their properties are easy to be controlled. This critical review focuses on the syntheses of CP nanostructures and nanocomposites by electrochemical polymerization. The applications of the nanomaterials in organic devices such as sensors, actuators and memory devices also will be discussed (111 references).

Conducting polymer nanomaterials: electrosynthesis and applications

Conventional and novel syntheses of silver nanoparticles are considered, their advantages and shortcomings are analysed. Attention is focused on the shape-controlled methods of preparation of nanosized particles. The unique optical and antibacterial properties of nanosilver and related applications are discussed.

https://iopscience.iop.org/article/10.1070/RC2008v077n03ABEH003751/pdf

Synthesis and properties of silver nanoparticles: advances and prospects

One-dimensional conducting polymer nanocomposites: Synthesis, properties and applications

WS2/CdS photocatalysts with different amounts of WS2 cocatalyst are prepared by loading WS2 on CdS with an impregnation–sulfidation approach. The transformation process of the tungsten species loaded on CdS together with the junctions formed between WS2 and CdS are clearly demonstrated with X-ray photoelectron spectroscopy and transmission electron microscopy. Photocatalytic H2 production on WS2/CdS catalysts under visible light (λ > 420 nm) shows that WS2 cocatalyst plays a crucial role in H2 production. Under optimum conditions, the rate of H2 evolution can be increased by up to 28 times when CdS was loaded with only 1.0 wt % WS2, and WS2 demonstrates a catalytic performance comparable or even superior to those of noble metals. Photocatalytic reaction results and electrochemical measurements indicate that the significantly enhanced H2 evolution of WS2/CdS catalyst mainly owns to the junctions formed between WS2 and CdS and the excellent performance of WS2 as a cocatalyst in catalyzing H2 evolution.

Photocatalytic H2 Evolution on CdS Loaded with WS2 as Cocatalyst under Visible Light Irradiation

Among the armoury of photovoltaic materials, thin film heterojunction photovoltaics continue to be a promising candidate for solar energy conversion delivering a vast scope in terms of device design and fabrication. Their production does not require expensive semiconductor substrates and high temperature device processing, which allows reduced cost per unit area while maintaining reasonable efficiency. In this regard, superstrate CdTe/CdS solar cells are extensively investigated because of their suitable bandgap alignments, cost effective methods of production at large scales and stability against proton/electron irradiation. The conversion efficiencies in the range of 6–20% are achieved by structuring the device by varying the absorber/window layer thickness, junction activation/annealing steps, with more suitable front/back contacts, preparation techniques, doping with foreign ions, etc. This review focuses on fundamental and critical aspects like: (a) choice of CdS window layer and CdTe absorber layer; (b) drawbacks associated with the device including environmental problems, optical absorption losses and back contact barriers; (c) structural dynamics at CdS–CdTe interface; (d) influence of junction activation process by CdCl2 or HCF2Cl treatment; (e) interface and grain boundary passivation effects; (f) device degradation due to impurity diffusion and stress; (g) fabrication with suitable front and back contacts; (h) chemical processes occurring at various interfaces; (i) strategies and modifications developed to improve their efficiency. The complexity involved in understanding the multiple aspects of tuning the solar cell efficiency is reviewed in detail by considering the individual contribution from each component of the device. It is expected that this review article will enrich the materials aspects of CdTe/CdS devices for solar energy conversion and stimulate further innovative research interest on this intriguing topic.

Physics and chemistry of CdTe/CdS thin film heterojunction photovoltaic devices: fundamental and critical aspects

Silver/polyaniline (Ag/PANI) nanowires are prepared by electropolymerization of aniline in porous anodic aluminum oxide (AAO) from an acidic electrolyte containing silver metal ions and aniline. Ag nanowires, PANI nanowires, and PANI thin films are made for comparative purposes. The nanowires are characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM) and X-ray diffraction. The HRTEM images illustrate that the composite nanowires consist of core Ag nanowires sheathed by polymer; i.e., they are nanocables. UV−visible absorption spectroscopy (UV−vis), Fourier transform infrared spectroscopy (FTIR), and Raman spectroscopy are done to investigate the chemical structure of the nanocables and any interaction between Ag and PANI. The Raman spectra indicate that the polymer is in the conducting emeraldine salt form and FTIR shows that there is some interaction between Ag and the acid protonated NH groups of polyaniline.

Fabrication and Characterization of Silver/Polyaniline Composite Nanowires in Porous Anodic Alumina

Investigation of electronic quality of chemical bath deposited cadmium sulphide layers used in thin film photovoltaic solar cells

Self-assembled nanocrystalline cadmium selenide (Q-CdSe) thin films of different grain size have been successfully deposited by wet chemical technique. The method allows a controlled formation of the self-assembled structure with different grain size by varying the concentration of surfactant (TOPO) in an electrolyte containing CdCl 2 , NH 4 Cl and Na 2 SeSO 3 at pH 8 and temperature 36 °C. Effect of particle size on the structural, optical and morphological properties has been studied and correlated. Atomic force microscopy investigation indicated that the as-deposited films were smooth, compact and exhibited tendency for self-organisation. Size of CdSe nanoparticles can be altered from 18 nm (bulk) to 2.3 nm. The nanocrystalline film shows hexagonal structure. Blue shift has been observed in optical absorption and photoluminescence spectra. The microstructural strain calculated from peak broadening revealed an increase in strain with decreasing particle size.

Self-assembled nanocrystalline CdSe thin films

http://www-g.eng.cam.ac.uk/nms/publications/pdf/King_OC2007.pdf

Shweta Chaure

Papers

Fabrication and Characterization of Silver/Polyaniline Composite Nanowires in Porous Anodic Alumina

Investigation of electronic quality of chemical bath deposited cadmium sulphide layers used in thin film photovoltaic solar cells

Self-assembled nanocrystalline CdSe thin films

Scattering induced optical limiting in Si/SiO2 nanostructure dispersions

Cd1−xZnxTe thin films formed by non-aqueous electrochemical route