This paper presents the preparation of multi-walled carbone nanotubes (CNTs) and CdS nanoparticles based hybrid materials. We aim at comparing two kinds of CNTs’ functionalization by thiol groups in order to demonstrate that the surface chemistry done on the CNTs can direct the morphology of the nanohybrids. Indeed, strong oxidation of CNTs leads to shorter nanotubes opened at their ends, allowing the grafting of mercaptotriethoxysilane whereas the generation of diazonium salts in presence of pristine nanotubes should lead to the functionalization of the whole lateral surface of the nanotubes. CdS nanoparticles can then be anchored to thiol groups, leading to interesting hybrid precursors for photovoltaic applications.

Among the different possibilities to control the size, the shape and the spatial organization of nano-objects, one consists in the use of the ordered mesoporosity of silica matrices as nanoreactors for their synthesis. This strategy has been used to elaborate Prussian Blue Analogues (PBA) exhibiting photomagnetic properties. Since the synthesis of these nanocomposites begins with the obtention of mesoporous silica monoliths containing Co2+ ions, we focus in this paper on the effect of the quantity of Co2+ ions and the amount of surfactant on the nanostructuration of these monoliths.

Systematic studies have been conducted on the electrical characteristics of poly(3-hexylthiophene)-based organic thin film transistors (OTFTs). The OTFTs have been characterized at low-operating voltages and deductions have been made regarding the current modulation mechanisms involved. Irreproducibility of transfer characteristics in these devices beyond a certain gate voltage, as well as a slow time-dependant component to drain current at certain gate voltages, indicates electrochemical changes occurring in the device during operation. It is hoped that this work can help to improve the understanding of OTFTs of this type and, in turn, their performance in the future.

The authors present electrical comparisons on an array of test structures including organic lateral diodes and thin film transistors (OTFT), fabricated with a range of disordered and polycrystalline organic semiconductors, to examine the increasing need for effective isolation for organic-based circuits. As the minimum feature size decreases, circuit components become closely positioned, which leads to increased electrical crosstalk. The organic semiconductors utilised for this work include solution-processable organic semiconductors such as disordered polymers P3HT and PTAA, and a polycrystalline material TIPS-pentacene. In order to predict the magnitude required for isolation for the different semiconductors, simple test structures have been designed consisting of two gold electrodes separated by a distance ranging from 4 μm up to 2000 μm. The bulk conductivity from such test structures provides the limits at which circuit components may be placed for crosstalk free operation. The work presented culminates in the development of an isolation layer to help reduce the off-currents and gate leakages of the OTFTs.

We present analytical models for organic thin film transistors (OTFTs) and Schottky diodes based on polycrystalline semiconductors. The OTFT model is developed using a well-established approach previously developed for polysilicon, with slight modification for organics. The model predicts voltage and temperature dependencies on the various device and circuit parameters. A good agreement is obtained with experimental data of TIPS-based OTFTs. Essential parameters such as the characteristic temperature and Meyer-Neldel Energy extracted using the model with TIPS OTFTs data were in agreement with those obtained from Schottky diode measurements.

Silicon nanocrystals (Si-NCs) are of significant research interest owing to their quantum confined photoluminescent (PL) properties and biological inertness. A promising application of these NCs is as the luminescent component in multifunctional biomedical technologies. In this report, we demonstrate the encapsulation of alkyl terminated Si-NCs within a mesoporous silica shell as a multifunctional imaging and drug delivery architecture. The Si-NC concentration was found to critically impact the nanoshell morphology. The impact of the encapsulation process on the Si-NC PL was studied, showing a blue-shift and decrease in intensity attributed to the oxidation of Si-NCs under basic conditions.

The present study investigates systematically, how the electrical properties of thin films consisting of silicon nanoparticles are affected by an organic monolayer coating the particles. Therefore, films of as-prepared silicon nanoparticles with a size of about 23 nm as well as freshly etched ones, both terminated with hydrogen, are compared with films of silicon nanoparticles functionalized with different 1-alkenes. It is found that the activation energy of the electron transport through the nanoparticle films scales with the thickness and permittivity of the respective organic monolayer.