The effect of exciplex dynamics on the device characteristics of organic semiconductor bilayer structures is explored. Exciplex formation, dissociation, and relaxation to the ground state are incorporated into a physics-based device model. The model is applied to both organic light emitting diodes and photovoltaic cells. In the examples, C60and tetracene parameters are used for the electron and hole transport layers, respectively.

Dye type solar cells, especially those incorporating low cost dyes suffer from a very narrow photo-response wavelength range. Motivated by natural photosynthesis research, energy relay dyes (ERDs) appear to offer a possibility to broaden the dye-cell spectral response. In-turn photovoltaic cells can be an extremely sensitive tool for investigation of dye ERD photochemistry. Sensitive Chlorophyll based dye-type solar cells were prepared from purified natural Chlorophyll A. The importance of Chlorophyll purity is discussed as well as the use of purified Chlorophyll A in combination with ERD’s. . Results shed light on many interesting phenomenon including the nature of purified Chlorophyll A excitation and absorption. Importantly, it was found by this work that the ERD architecture when combined with a photosensitizer do not appear to having greater absorption in the infrared region of the spectrum than the ERD alone indicating a lack of cooperative absorption.

In this work, we prepared graphite oxide (GO)/polyaniline nanocomposites by enzymatic polymerization of aniline in an aqueous dispersion of graphite oxide. Two GO dispersions with sheets having an average lateral size of 12.50 μm and 247 nm were used. The enzymatic polymerization was carried out in aqueous acidic medium using toluenesulfonic acid (TSA) as doping agent, horseradish peroxide (HRP) as catalyst, and hydrogen peroxide as oxidizer. The polymerization reaction was studied using 1.0, 2.5 and 5 wt % of GO and nGO dispersions. No changes were observed in the catalytic activity of the peroxidase during the enzymatic synthesis due to the additionof GO sheets. Scanning electron microscopy images show that PANI colloids were attached on GO sheets. The PANI-GO colloids were characterized by ultraviolet–visible spectroscopy and Fourier transformed infrared spectroscopy, whereas their colloidal stability was evaluated at different pHs. The UV-vis spectroscopy study revealed that GO affects the electronic conjugation of PANI modifying its absorption spectrum.

Semi-conducting conjugated (co)polymers are well soluble and can be processed easily in a large scale. Among these materials, rod-coil block and graft copolymers, show very particular properties of self-assembly, and are very promising in organic electronic, as organic photovoltaic materials for example.

The post-functionalization of poly(3-hexylthiophene) (P3HT) from ω-allyl terminated P3HT via various synthetic routes is reported in order to obtain well-defined block and graft copolymers for optoelectronic or photovoltaic applications. First, a well-defined and monofunctional P3HT-based macro-initiator has been obtained through a clean and versatile process. Well-defined rod-coil block copolymers were obtained by nitroxide mediated radical polymerization (NMRP) with various monomers. Finally, three different novel P3HT-based graft copolymers were synthesized following two routes.

Poly(3,4-ethylenedioxythiophene) (PEDOT) electrodes are prepared by a novel ultrashort galvanic pulse electropolymerization technique for application in solid-state supercapacitors. Microstructure studies using scanning electron microscopy (SEM) show that PEDOT electrodes deposited by pulse polymerization are highly porous as compared to the conventional potentiostatic polymerization. In addition, as revealed by the X-ray photoelectron spectroscopy (XPS) studies in the PEDOT films formed by pulse polymerization, the polymer chains are fully conjugated with the dopant ClO4- ions. Solid-state supercapacitor cells using pulse polymerized PEDOT electrodes and ionic liquid gel polymer electrolyte were fabricated and characterized. The impedance spectroscopy studies show that the pulse polymerized PEDOT electrode have specific capacitance value of ∼ 65 F g-1 as compared to ∼52 F g-1for potentiostatically polymerized PEDOT and significantly lower interfacial and charge transfer resistance. Cyclic voltammetry (CV) and galvanostatic charge-discharge characterization show highly capacitive behavior of the supercapacitor cells in the solid-state configuration.