Recent use of quantum mechanics to guide the improvement of molecular hyperpolarizability and the use of statistical mechanical analysis of the effects of intermolecular electrostatic interactions to improve the acentric ordering of organic chromophores has led to the realization of electro-optic coefficients, r₃₃, greater than 100 pm/V (at telecommunication wavelengths). This material design and development paradigm is likely to lead to further improvement in electro-optic activity, which will in turn facilitate the development of a variety of electro-optic devices with drive (V_π) voltage requirements of less than one volt. The utility of organic electro-optic materials for development of high bandwidth devices is now well documented. What is less obvious is the utility of organic electro-optic materials for the fabrication of complex (including conformal, flexible, and three-dimensional) device structures. In this communication, we review recent improvements in electro-optic activity; thermal and photochemical stability; and processability of organic electro-optic materials and the use of these materials to fabricate conformal and flexible electro-optic devices and devices based upon single and multiple coupled ring microresonators.

We present recent developments in etchless fabrication techniques for defining low-loss waveguides in polymers. Photobleached waveguides with optical propagation loss equal to the inherent loss of the core materials have been fabricated, as well as Mach-Zehnder modulators with 4.5 volt driving voltage and fiber-to-fiber insertion loss of 8 dB. In terms of new configurations, a novel linearized directional coupler modulator that has a 10 dB enhancement in the dynamic range compared to conventional Mach-Zehnder modulators is presented. We report on the design and fabrication of polymer digital optical switches with switching voltages of 7 volts and extinction ratios greater than 20 dB. Simultaneous serrodyne frequency shifting and high-frequency phase modulation in a polymer phase modulator are demonstrated in order to simplify the setup required to implement two-color heterodyne ranging. Finally, we propose implementations of optical signal processors based on polymer optical delay lines, couplers, and electrooptic modulators, and discuss their applications to optical signal processing.

We report hybrid electro-optic (EO) polymer/sol-gel waveguide modulators with a structure for an EO polymer confined laterally in a sol-gel over cladding, which is fabricated by all-wet etching process. The structure enables an adiabatic transition between the sol-gel waveguide and thick EO polymer overlayer. Intensity mode is confined well in 0.9-μm-thick EO polymer overlayer, which reduces a half wave voltage (V_π) due to increased overlap integral in the hybrid EO modulator. Straight channel birefringence EO modulators with the structure reduce the V_π by the factor of 4 after guided wave well confined in the EO polymer. The straight channel waveguide modulator with 2.4-cm-long electrode demonstrated the V_π of 13 V. Preliminary testing results using a Mach-Zehnder waveguide modulator were investigated to reduce the V_π further.

Recent development of high-performance nonlinear optical polymers for electro-optics (E-O) is reviewed in this paper. A highly efficient and thermally stable nonlinear optical (NLO) chromophore, namely 2-[4-(2-{5-[2-(4-{Bis-(tert-butyl-dimethyl-silanyloxy)-ethyl]-amino}-phenyl)-vinyl]-thiophen-2-yl}-vinyl)-3-cyano-5-trifluoromethyl-5H-furan-2-ylidene]-malononitrile, has been prepared and incorporated in amorphous polycarbonate (APC) composites. The result from high electric field poling shows a very large E-O coefficient (r₃₃ = 94 pm/V at 1.3 μm), ~80% of which can be maintained at 85 °C for more than 500 hours. In addition to this guest/host sysytem, a high Tg side-chain polymer, derived from a 3-D cardo-type polimide with dendron-encapsulated chromophores as pendent groups has also been synthesized and characterized. A high degree of chromophore dipole orientation and a large r₃₃ of 71 pm/V at 1.3 μm can be achieved in this poled polyimide. More than 90% of its E-O activity can be maintained at 85 °C for more than 600 hours. To access the full potential of poled polymers for device applications, we have developed a new lattice-hardening approach to overcome the “nonlinearity-stability-tradeoff” of conventional thermoset methods. By using the Diels-Alder lattice-hardening process, we can achieve the same high poling efficiency and large r₃₃value as in a guest-host system while maintaining good thermal stability seen in densely-crosslinked polymers. By modifying the electronic properties of the crosslinking reagents, we can fine-tune the processing temperature window of the Diels-Alder reactions to achieve hardened materials with optimal properties.

Drawing on the success of the DH6-polycarbonate system, new derivatives based on the DH bridge structure, bis-1,2-(dibutoxythiophene)vinylene have been synthesized and tested. The property-structure function has been investigated, showing that location of the trifluorovinylether (TFVE) crosslinker on the chromophore has an impact on electro-optic (EO) activity as well as stability. A crosslinked polymer, IMOH_PCT-R and a linear high glass transition (T_g) analog, IMOH_HT, in combination with various DH derivatives are discussed. The temporal stability data of these systems show comparable results for both crosslinked and linear polymers, furthering the argument that the T_g of the EO material is the critical parameter in determining device lifetime.

The growth, synthesis and characteristics of a new organic nonlinear optical crystal, a derivative of Schiff base compounds, 4-nitrobenzylidene-4-chloroaniline are reported. Good-quality crystals have been successfully grown using Bridgman-Stockbarger (BS) Technique. The organic crystal, 4-nitrobenzylidene-4-chloroaniline, shows good second harmonic generation of 1.064 micron wavelength. A recent work done on the semiorganic nonlinear crystals are reviewed along with results of growth of a few L-arginine phosphate type crystals is presented.

Due to they can be tailored to provide a wide range of physical properties and their easiness of processing and fabrication, polymeric materials have found widespread use in the manufacture of microwave, electronics, photonics and bio-tech systems. This paper presents the basic principle of phase modulation spectroscopic ellipsometer (PMSE) and its advantages over other ellipsometry in measuring polymer film. Used for thin film measurements ultra-thin dielectric, meal film and organic film, the PMSE technique is now used over a wide spectral range from the vacuum ultraviolet to the mid infrared. Film thickness ranging from Angstrom up to 50um can be measured by PMSE. Applications of PMSE on measurement and characterization of polymer/organic material are given in the paper.

Deoxyribonucleic Acid (DNA) extracted and purified from salmon sperm was investigated for use in electro-optic devices as a cladding layer. The 500,000 molecular weight material has a refractive index less than that of common core materials such as poly(methyl)methacrylate (PMMA) and amorphous polycarbonates, shows a resistivity two orders of magnitude lower than common core materials, and shows no signs of degradation within 100°C of the host poling temperature. DNA was analyzed as a cladding material for two different chromophore systems, Disperse Red 1 (DR1), and Cheng-Larry Dalton 1 (CLD1) in a PMMA guest/host system. A baseline device, comprised only of a 1.7μm layer of PMMA, was tested for non-linearity with each chromophore, with the r₃₃ value increasing with increasing temperature and voltage. Doublestack devices included a 1μm thick DNA film as the cladding layer with the baseline core layer above. Based on the dielectric properties of DNA, values of r₃₃ were calculated for the theoretical behavior of the devices. The recorded r₃₃ values were accurate within 5% of the calculated values with the DR1 chromophore, and within 20% with the CLD1 chromophore, hence showing good device reproducibility.

A silica waveguide employing an electrooptic Kerr material as a functioning cladding is shown to modulate light at RF frequencies. The modulator uses a Kerr electrooptic material as the functional cladding on a silica waveguide structure. The modulator is designed to operate at 70 C and the electrooptic material has an index of refraction that is less than the silica waveguide at that temperature. Kerr-based materials have a refractive index that varies as the square of the applied voltage. This quadratic relationship is exploited by combining a DC bias voltage with the RF drive signal in order to reduce the drive voltage of the modulator.

We developed an amorphous polymer of cyclized perfluoropolymer (CPFP) which is highly transparent throughout the visible range and fabricated waveguides of the polymer for visible light. At the wavelength of 405 nm, approximately 60% of lightwaves are propagated through the straight waveguide and over 50% of lightwaves are propagated through the buried waveguides with a radius of more than 30 mm, demonstrating the feasibility of the waveguides as light sources with a low numerical aperture in a single mode. The waveguides are prospective candidates for a multi-beam light source for parallel information processing such as optical recording systems.

A new method of interconnecting various optoelectronic components is discussed. Offset error up to 25 microns can be corrected to achieve single mode alignment accuracies. Several planar optical devices were photocomposed using the adaptive photolithographic method and these have been shown to perform with the desired characteristics.

We have developed a simple process method, "vapor transportation method", for surface treatments and functionalization of polymeric materials. The method is addition of versatile functions to the solid polymeric materials with treatment of vapors under vacuum. Polymeric waveguides can be easily fabricated using the method. Exposing rods of transparent polymer, poly(methylmethacrylate) (PMMA), by vapor of organofluorine compounds, fluorinated esters, with lower refractive indices made the organofluorines dispersed into the PMMA from the surface. The refractive index of the organofluorine-doped PMMA surface was decreased and a cladding layer was formed. The core was the central part of the rod, which was the PMMA without dispersion of organofluorines. The properties of the waveguides made by the method were characterized. The refractive index and thickness of the cladding layer can be controlled by conditions of vapor transportation, such as treatment time and temperature.

High resolution gratings for the application of optical waveguide devices are fabricated using a series of photopolymers. The relief gratings were formed by the two-beam interference ablation technique using a third-harmonic generation of a Nd:YAG laser (355nm) onto polyimide and electrooptic polymer films. In polyimide films, the gratings with a period of 400nm and a depth of about 280nm were fabricated by the single-pulse irradiation. We tried to fabricate the gratings using a photoresist accompanied with wet development using an Ar⁺ laser (488nm). By wet development process, higher aspect and clearer periodical structure at a depth of 320nm and a period of nearly 500nm was realized. High diffraction efficiency of 55.4% was measured from the relief grating. We also replicated the grating to UV curable epoxy resin as an embossing master for the fabrication of waveguide devices.

Simple liquid crystal panel equipped with a polymeric photoconducting layer can be used for displaying dynamic holographic images. It is sufficient to compute the hologram of the object and reconstruct the wavefield optically. This can be done by projection of the binary hologram onto liquid crystal panel with the help of standard video-projector. Illumination of the photoconducting polymeric layer by a white light interferogram leads to tiny molecular rearrangements within the bulk of the liquid crystal layer which form a refractive index grating. They occur as a result of spatially modulated electric space charge field produced in a polymer. Short holographic films displayed at video-rates are achievable with the system based on PVK:TNF polymer and planar nematic liquid crystal mixture. The underlying electrical and optical processes as well as characteristics, performances and limitations of the system are discussed.

We demonstrate the possibility of photodimerizable chromophores attached to a short peptide chain as potential media for high capacity optical storage. The chromophores used in the present case are bromo-, chloro and fluorouracil.

Optically controlled spatial light modulator was demonstrated as application of photorefractive polymeric material. Since photorefractive composite based on carbazole-substituted polysiloxane matrix (PSX-Cz) has an advantages of stability in phase separation, compared to poly(N-vinyl carbazole) based composite, we can dope almost all kinds of chromophore with the PSX-Cz to prepare a photorefractive composite. Here a chromophore 2-[3-[(E)-2-(piperidino)-1-ethenyl]-5,5-dimethyl-2-cyclohexenyliden] malononitrile (P-IP-DC), with large dipole moment and large polarizability anisotropy was adopted into a photorefractive sample, which showed a high diffraction efficiency of 85 % at an external field of 28 V/μm. Using this photorefractive composite, incoherent image imposed in Xe-lamp light was converted into coherent image in He-Ne laser light by the optically controlled spatial light modulator.

In this paper we present experimental results of study of liquid crystal panels (LCP) designed for dynamic holography, with new photoconducting and photorefractive elements as their parts. We used either microcrystals or photochromic molecules which were added to the liquid crystal mixture, alternatively photoaligning polymers or polyvinyl carbazole doped with trinitroflourenone (PVK:TNF) and polyoctylthiophene as photoconducting layers were employed. Studies of light diffraction efficiency (η) were made in a typical degenerate two-wave mixing experiments (DTWM). We report here results of maximum diffraction efficiencies obtained for different type of LCPs. The highest η was measured in LCP with PVK:TNF layer (η=32%) and the lowest were reported for LCP containing microcrystals (η=0.01%). Best of developed LCPs were used as media for dynamic holographic applications. Elimination of phase distortion in degenerate four-wave mixing (DFWM) experiment, reconstruction of binary holograms and optical correlation are only few representative examples of applications demonstrated recently in our laboratory.

The nonvolatile transistor memory element is an interesting topic in organic electronics. In this case a memory cell consists of only one device where the stored information is written as a gate insulator polarization by a gate voltage pulse and read by the channel conductance control with channel voltage pulse without destruction of the stored information. Therefore such transistor could be the base of non-volatile non-destructively readable computer memory of extremely high density. Also devices with polarizable gate dielectrics can function more effectively in certain circuits. The effective threshold voltage V_t can be brought very close to zero, for applications where the available gate voltage is limited. Resonant and adaptive circuits can be tuned insitu by polarizing the gates. Poly(vinylidene fluoride), PVDF and its copolymer with trifluoroethylene P(VDF-TrFE) are among the best known and most widely used ferroelectric polymers. In this manuscript, we report new results of an organic FET, fabricated with pentacene as the active material and P(VDF-TrFE) as the gate insulator. Application of a writing voltage of -50 V for short duration results in significant change in the threshold voltage and remarkable increase in the drain current. The memory effect is retained over a period of 20 hours.

Organic compounds that undergo strong nonlinear, multiphoton absorption have been gaining greater interest, mainly in the developing fields of multiphoton fluorescence imaging, optical data storage, 3-D microfabrication, and photodynamic therapy. Systematic studies have shown that conjugated organic molecules with large delocalized π electron systems show very large nonlinear optical effects. Two-photon absorbing chromophores have also been incorporated into dendrimers to increase two-photon absorptivity. A cooperative enhancement of two-photon absorption (2PA) has been observed, such as in the linkage of branched chromophores through a common amine group and chromophore-metal complexes. This enhancement may be related to extensive two-dimensional π-delocalization in these molecules. Herein, we describe the synthesis, structural characterization and photophysical study of a series of compounds (model, oligomer, and polymer) with symmetric molecular structure of the D-π-D motif and branched D-π-D dendrimeric structures based on substituted fluorene derivatives. Femtosecond 2PA cross sections were very large for some derivatives (over 10,000 GM) and often exhibited substantial solvent effects.

A detailed study was conducted for two-photon absorption of a selected group of new derivatives of cyclohexanone/piperidone with regard to their molecular structure and the feasibility of using these derivatives as nonlinear optical absorbers for optical limiting. Derivatives of cyclohexanone/piperidone have a cross-section of two-photon absorption of the order of 3000 x 10^-50cm⁴s/photon and compare well against known two-photon absorbers. This makes them promising nonlinear optical absorbers and optical limiters. Their important feature is that the energy is absorbed in the infrared region, where the protection is needed for remote IR sensors and night-vision systems. It is also important that the energy of the dissipated infrared radiation is converted mostly into fluorescence but not into heat that can damage optical limiter.

Physical Sciences Inc. has several ongoing programs to develop novel high-damage-threshold solid-state optical limiters. We are using polymer matrices doped with RSA (reverse saturable absorber) chromophores such as metallo-phthalocyanines to create both a tandem optical limiter and a graded-density limiter. Characterization is performed using a novel f/5 optical setup which simultaneously measures spatial and temporal profiles of the transmitted light as well as the conventional average transmission. A Q-switched doubled Nd:YAG is used as the probe laser. In this paper, we present detailed spatial and temporal characterization of solid-state tandem optical-limiter devices. To our knowledge, few such measurements have been conducted on limiting materials. Our initial results indicate that for these materials, damage typically occurs within two nanoseconds of the damaging pulse. In addition, CCD images reveal the spatial evolution of the nonlinear absorption of the pulse as it interacts with the limiting material at energies ranging from microjoules to millijoules. Lastly, time-resolved damage measurements were conducted on PMMA. These results as well as others which elucidate the limiting and damage dynamics will be presented.

The luminescent properties of organic infrared (IR) and near-infrared (NIR) light-emitting materials were investigated for optical communication applications. These materials consisted of two organic ionic dyes, (2-[6-(4-dimethylaminophenyl)-2,4-neopentylene-1,3,5-hexatrienyl]-3-methyl-benzothiazonium perchlorate) (LDS821) and [C₄₁H₃₃Cl₂N₂]⁺•BF^4- (IR1051), and an organic rare-earth complex, erbium (III) tris(8-hydroxyquinoline) (ErQ). The three materials are both photoluminescent and electroluminescent in the 0.8-, 1.1- and 1.5-μm wavelength regions, respectively, and so can be used as optically active species in devices operated by either optical or current excitation. Three device forms were fabricated with these light-emitting materials as optically active species, namely vacuum-deposited or spin-coated polymer thin-films, monodispersed polymer microparticles and embedded polymeric optical waveguides. Their luminescent processes are discussed and possible optical communication applications are proposed.

We have successfully incorporated a near-infrared-emitting compound, 2-(6-(4-Dimethylaminophenyl)-2,4-neopentylene-1,3,5-hexatrienyl)-3-methyl-benzothiazolium Perchlorat, into poly(1-vinyl-2-pyrrolidone)-base planar waveguides. The variable-stripe-length method is employed to deduce the net gain coefficient of the waveguides, 1 cm in length, doped with 0.5 wt.% of the compound. The gain spectroscopy has revealed a moderate net modal gain of 2.6 cm^-1 at 820 nm for the pump fluence of 22.6 μJ/cm² (3.8 kW/cm²). The waveguides have exhibited lasing at 820 nm when they are transversely photoexcited at 532 nm with a nanosecond Nd: YAG laser. The Fresnel reflection at the polymer-air interfaces acts as a low-finesse Fabry-Perot cavity. The threshold for lasing has been found to be 24.5 μJ/cm² (4.1 kW/cm²).

The use of conjugated light emitting polymers (LEPs) blended in non-conjugated matrices offers an enhancement in electroluminescence efficiency in polymer light emitting diodes (PLEDs) since the aggregate quenching of the excited state emission is ameliorated. In such a scheme the matrix polymer may be developed in order to enhance the thermal, mechanical, and processing properties of the LEP blend as a whole. We have produced solution processable blends of polyfluorene (PF) based copolymers with thermally crosslinkable perfluoroarylether (PFAE) polymers and tested these materials' performance as a single emissive layer in the simplest PLED structure. Specifically we present results of blends consisting of red poly[{9,9-dihexyl-2,7-bis(1-cyanovinylene)fluorenyl-ene}-alt-co-{2,5-bis(N,N'-diphenylamino)-1,4-phenylene}] as the LEP and a novel PFAE which is thermally crosslinked as the matrix. The new PFAE has been specifically developed for low optical loss, high glass transition temperature (T_g), and solution process-ability. Once spun cast and thermally crosslinked, films of these polymer blends show increased solvent resistance and enhanced T_g due to the fluoropolymer matrix. Simple ITO/polymer/Al PLEDs of several concentration ratios are fabricated and tested in order to determine the efficacy of various matrix additions. The light-current density-voltage characteristics show either equivalent or enhanced efficiency depending on LEP/PFAE concentration. Blends of the PFAE and PF copolymer LEPs are patterned into 6μm waveguide structures utilizing the solvent resistance afforded by the crosslinked PFAE matrix.

On the basis of the investigation into organic thin films preparations and device, the Organic Light-Emitting Device (OLED) with mutual doped transitional layer was designed and fabricated, mutual doped layer of N,N’-bis-(1-naphthyl)-N,N’-diphenyl-1, 1’-biphenyl-4,4’-diamine (NPB) and aluminum tri(8-hydroxyquinoline)(Alq₃) was used as emitting layer. Rate of NPB to Alq₃ was 10:1 at anode to 1:10 at cathode. Light-emitting performance of the OLED was analyzed. Compared with conventional device in which Alq₃ was used as emitting layer and blending device in which blending layer of NPB and Alq₃ was used as emitting layer, the device performance of mutual doped transitional layer was evidently improved because of the interface and the waveguide effect were eliminated effectively.

Light-converting polyethylene film containing Eu(III) complex with phenanthroline was manufactured under an extrusion process. The film was characterized by means of time-of-flight secondary-ion-mass spectrometry (TOF-SIMS), ultraviolet-visible-infrared (UV-Vis-IR) spectroscopy, study of excitation and luminescence spectra, quantum yield and lifetime of luminescence. TOF-SIMS surface mapping showed the uniform distribution of Eu(III) over the film. Typical Eu(III)-phenanthroline complex excitation and fluorescence spectra were recorded, the quantum yield of fluorescence being 5±2%. Luminescence lifetime was measured as 0.4 ms. Visualization of strong subpicosecond UV laser beams through the use of developed film has been demonstrated.

Photonics devices based on polymer optical waveguides are widely studied now and some commercial announcements have already been published. Nevertheless they are not been followed by really available products and it is still necessary to improve such kind of devices. The aim of this paper is to present a new structure for a polymer electro-optic modulator. The electro-optic polymer material is PMMA-DR1. This electro-optic polymer is well known by its high frequency bandwidth of modulation and its functional robustness. Nevertheless, its half-wave voltage remains relatively high, that is why a new configuration is proposed decreasing the half-wave voltage. The new device, which is fully described, is based on the classical Mach-Zehnder optical modulator structure, to which a completely new loop structure is added. Thus the optical waveguides are designed in order to increase the active length and so reducing the half-wave voltage. Otherwise the device is designed for a complete planar realization. The RF strip lines are also designed according to the loop structure with 50Ω characteristic impedance. A device has been realized and its optical are checked at 1.55μm wavelength. Electronic characteristics should be determined by the way of spectrum and network analyzers at frequencies up to 2GHz. All the measurements should show the feasibility and efficiency of the new structure.

In pursuit of greater understanding of structure property relationships in NLO chromophores, a series of molecules consisting of three aromatic rings was synthesized. The relative positions of benzene and thiophene rings in these molecules were varied. Theoretical calculations also suggest that the use of a slightly electron deficient heteroaromatic, such as thiazole, can increase β through the concept of an electronic gradient. The use of this heteroaromatic in the correct orientation can compensate for the energetic barrier that benzene presents during charge-transfer. Hyper-Raleigh Scattering (HRS) measurements on three of these “gradient bridge” type chromophores show that benzene located at the donor end provided the highest hyperpolarizability. The poor solubility of these three-ring systems severely limited their processability and gave considerable synthetic challenges. The difference in theoretical and experimental trends of β are discussed.

Density functional theory calculations were used to develop understanding of the effects of differing substitution patterns in multiply donor and acceptor substituted nonlinear optical chromophores. A novel series type substitution design was presented and evaluated. Calculations were performed for a number of structures and hyperpolarizability values were compared. The data obtained showed an increase in molecular first hyperpoloarizability in multifunctional chromophores based on this series type design as compared with linear molecules constructed from the same donor-bridge-acceptor components. This data was then used to direct the synthesis of novel nonlinear optical chromophores.

Optical properties of spiropyran-doped DNA-CTMA films have been studied. They strongly depended on molar ratio of DNA/spiropyran. Switching experiments was performed for 1.55-μm signal light. Measured slow transition times indicate much precise adjustment and optimization.

Fabrication method of large core polymeric optical waveguides by three-time replication of anisotropically etched (110) single-crystal silicon original molds is proposed. Those replication processes consist of soft lithography, UV embossing and hot embossing. Original masters for this replication process were fabricated by anisotropic etching of (110) single-crystal silicon wafers by a strong alkali solution. The optimum conditions of anisotrophic etching are etching temperature of 60° C and the alkali solution concentration of less than 30wt%. Original masters replicated to silicone rubber molds by soft lithography. Then, using UV embossing, the silicone rubber molds replicated to an UV-curable resin for hot embossing stampers. The stampers by hot embossing replicated to rectangular groove PMMA replicas that act as undercladdings for optical waveguides. The optimum conditions of hot embossing are the heated temperature of over 130° C, the pressure of more than 50kgf and the removal temperature of less than 110° C. In this work, channel optical waveguides with 100, 300, 500 μm core size were fabricated by controlling the pattern width of silicon and etching time of silicon. Low Propagation losses of 0.30, 0.22 and 0.19dB/cm at 650nm were realized for 100, 300, and 500 μm core waveguides, respectively.

A series of soluble, fully aromatic polyetherimides were prepared as candidate materials for optical coating applications. Most of the new polymer coatings possessed high transparency in the optical and near-infrared spectral regions at thicknesses ranging from 1 to 10 microns. The refractive indices obtained ranged from 1.60 to 1.80 at visible wavelengths, with the highest values generally being obtained near 400 nm followed by a gentle decline as wavelength increased to 700 nm and beyond. The refractive index values could be controlled by varying the dianhydride and diamine composition. All of the polyimides showed good thermal stability to 400°C and displayed glass transition temperatures above 220°C, making them excellent candidates for device applications where increased refractive index and high optical clarity are desired. The paper will discuss the preparation and physical and optical properties of the polymers and compare them to other high index coating systems.

Organic solar cells based on interpenetrated network of conjugated polymer as donor and fullerene derivative as acceptor materials have a great potential for improvement of the efficiency. We fabricated a device based on a composite of poly(2-methoxy-5-(2'-ethylhexyloxy)-1,4-phenylenevinylene (MEH-PPV) and [6,6]-phenyl C₆₀ butyric acid methyl ester (PCBM). Surface treatment, insertion of interfacial layers, and improvement of the morphology of the active layer significantly increase the photovoltaic performances of the structure. We obtained an open circuit voltage of 0.87 V and short circuit current density of -8.4 mA/cm² under 100 mW/cm² AM 1.5 solar simulator illumination, yielding a 2.9 % power conversion efficiency. Two others fullerene derivatives were synthesized in order to get a stronger acceptor. The electrical and optical properties of devices made with MEH-PPV and these acceptors are investigated.

Future generations of flexible, transparent electronics require the use of polymer based thin-film transistors (TFTs) with high carrier mobility. The problem of enhancing TFT characteristics is addressed in this report. Systematic studies were performed to optimize the thickness and composition of the active and dielectric layers. Different electrode materials were tested along with “top” and “bottom” device configurations. Various coating techniques (SAM) were applied to achieve a higher degree of order in polymer chains of semi-conducting layer. Results demonstrate the influence of the mentioned factors on the TFT performance, including increase of mobility and on/off ratio.

The AC and DC conductivities of pyroelectric composite, deuterated triglycine sulfate (DTGS): polyvinylidene fluoride (PVDF) having 15%, 20%, and 40% DTGS content (by weight) have been measured at temperature ranging from room temperature to 55 °C. The ac conductivity of composites at 1 MHz shows very weak temperature dependence. The dc conductivity for 20% and 40% DTGS content (by weight) composites shows activated behavior.

As conductor polymers and organic materials as Polyacetylene was first doped material, however present high sensitivity to environment, while the polyanilines present high stability in this conditions, so dimetylaniline doped in acids conditions shown good electricity conductivity material without polymerization in their structure, since can use a commercial polymer to maintain cohesion among the molecules, as the adhesive UHU, basically compound by polyvinyl acetate. We use this adhesive blended with hydrochloric acid adding later on dimethylaniline, controlling the quantities of hydrochloric acid and dimethylaniline determining so the coloration and the resistivity of the material, presenting clear brown color to produce the acid excess, with grizzly green color correspond to dimethylaniline excess. The resistivities are of 3 to 4 KΩ to be in solution, with gel consistency their resistivity it varies the order of 58 to 100 kΩ.

Characteristics as a blue clear appearance, viscous solution, odorless are some properties from Polyvinyl alcohol (APV), as a dry film it is clear transparent, shows high flexibility and it is a good insulator. This polymer does not contain double link then it does not have π orbital that permit an inherently conductivity when it is doped. However, can be doped with salts as nickel chloride hexahydrate NiCl₂6H₂O constructing a good conductor polymer with a resistivity around 300Ω cm. This doped polymer shows high dependency to the oxygen molecule by its molecular form or its presence in the humidity of the atmosphere. If a high vacuum is applied in a reactor with the doped polymer the value of resistivity increases quickly. The material shows a light reduction of resistivity parameter when its temperature is increased. Finally the polymer doped maintains high flexibility opening new possibilities and applications.

The dynamic holography method is applied to determine the response time for trans-cis-trans izomerization process in DR1 chromophore embedded in a solid polymer matrix. The experiments were performed on free standing films using a pulsed ps laser for grating writing and a cw laser for it reading. It is found that the writing process may be well described by a mono-exponential curve with a time constant below ms while the decay process is more complicated and can be approximated by a bi-exponential equation with two response times, significantly larger than for the writing process.

In the present work, a new type of photopolymer containing nano-sized photosensitive domains was proposed and optical properties including diffraction efficiency and optical transparency were investigated. By introducing nano-sized photosensitive domains, the phase stability of the photopolymer was greatly enhanced and recording stability was also enhanced.