Conductive polymer

About: Conductive polymer is a research topic. Over the lifetime, 21817 publications have been published within this topic receiving 692491 citations. The topic is also known as: intrinsically conducting polymer & ICP.

Molecular organic light-emitting diodes using highly conducting polymers as anodes

Abstract: Films fabricated from commercially available poly(3,4-ethylenedioxythiophene) poly(styrenesulfonate) (PEDOT:PSS) aqueous dispersions have been widely used in many electronic and optoelectronic applications. Previous attempts to utilize them as anodes in organic light-emitting diodes (OLEDs) were not satisfactory due to their low conductivity. In this letter we report on the fabrication and characterization of an OLED device made using a highly conductive form of PEDOT:PSS as anode and demonstrate its superior performance relative to that of a similar device using the commercial conducting polymer as an anode. An external electroluminescence quantum efficiency of ∼0.73% was measured at 100 A/m2.

Three-Dimensional Networked Metal-Organic Frameworks with Conductive Polypyrrole Tubes for Flexible Supercapacitors.

Abstract: Metal–organic frameworks (MOFs) with high porosity and a regular porous structure have emerged as a promising electrode material for supercapacitors, but their poor electrical conductivity limits their utilization efficiency and capacitive performance. To increase the overall electrical conductivity as well as the efficiency of MOF particles, three-dimensional networked MOFs are developed via using preprepared conductive polypyrrole (PPy) tubes as the support for in situ growth of MOF particles. As a result, the highly conductive PPy tubes that run through the MOF particles not only increase the electron transfer between MOF particles and maintain the high effective porosity of the MOFs but also endow the MOFs with flexibility. Promoted by such elaborately designed MOF–PPy networks, the specific capacitance of MOF particles has been increased from 99.2 F g–1 for pristine zeolitic imidazolate framework (ZIF)-67 to 597.6 F g–1 for ZIF–PPy networks, indicating the importance of the design of the ZIF–PPy cont...

A Semi-transparent Plastic Solar Cell Fabricated by a Lamination Process†

Abstract: Polymer solar cells have attracted broad research interest because of their advantageous solution processing capability and formation of low-cost, flexible, and large area electronic devices. However, the efficiency of polymer solar cells is still low compared to that of inorganic solar cells. Therefore, it is a challenge to find a polymer that has all the required properties for high efficiency devices, such as strong and broad absorption, high carrier mobility, and appropriate energy levels. One possible solution to avoid the strict material requirements is to stack two or more devices with different spectral responses, which enables more efficient utilization of solar energy. Such a solution would require a semitransparent solarcell device with high efficiency in its absorption wavelength range, while high transparency would be required in the complementary wavelength range. Semitransparent solar cells are also interesting for other appealing applications, such as energy-generating color window glasses. It is desirable that such solar cell devices can be fabricated using a low-cost strategy, such as the roll-to-roll fabrication process. One critical issue in this fabrication process is how to form the active-layer/cathode mechanic and electronic contacts. The lamination process is one very promising technique to fulfill this requirement owing to its simplicity and low cost. It has been reported to produce two-layer heterojunction solar cells; however, the method is not applicable to bulk heterojunction solar cells, nor compatible with roll-to-roll fabrication process. In this Communication, an electronic glue-based lamination process combined with interface modification is presented as a one-step process for semitransparent polymer solar-cell fabrication. The finished device is metalfree, semitransparent, flexible, self-encapsulated, and highly efficient (with a maximum external quantum efficiency of 70 % and power efficiency of 3 % under AM 1.5 global 1 sun solar illumination conditions with spectral mismatch correction). This approach represents a critical step towards the ultimate goal of low-cost polymer solar cells. The device fabrication process is illustrated in Figure 1, and can be described by the following steps. In Step I, two transparent substrates coated with a transparent conductor such as indium tin oxide (ITO), fluorine-doped tin oxide (FTO), or a high conductivity polymer, etc., are selected. In Step II, one substrate is coated with a very thin buffer layer (Cs2CO3 ) to act as the low-work-function cathode, followed by coating of the active polymer layer. Step III involves the coating of conductive polymer glue to the other transparent substrate. We used modified conducting polymer poly(ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) as the electronic glue, which was spin-coated to form the adhesive anode. Step IV is the lamination process: after drying both the substrates, they are laminated together by exerting force so that the two substrates are tightly glued together. During this lamination, a plastic rod with proper hardness rolls the plastic substrate to remove air bubbles. Both substrates are heated to a temperature of 105–120 °C during the lamination process, and the finished devices are then kept on the hotplate for 5–10 min for the final heat treatment. The PEDOT:PSS was purposely modified to become adhesive, so that the two separate films formed good contact at the interface, both electronically and mechanically. In this work, this adhesive and conductive PEDOT:PSS layer was obtained by doping D-sorbitol or volemitol into PEDOT:PSS, as has been successfully demonstrated in polymer light emitting diodes. However, the efficiency of such a device is too low for application. The polymer blend used in this work is regioregular poly(3-hexylthiophene):[6,6]-phenyl-C61-butyric acid methyl ester (RRP3HT:PCBM) in 1:1 w/w ratio. The 200 nm thick polymer blend film was deposited by the slow-growth method (or solvent annealing) to enhance device efficiency. Either glass or plastic can be used as the transparent substrate. Figure 1b shows a picture of an all-plastic solar cell. The device area is ca. 40 mm. With both cathode and anode being transparent, a semitransparent polymer solar cell is formed. The transparency (T%) of the device is shown in Figure 1c, together with the solar illumination spectrum. A transparency of around 70 % was obtained in the wavelength range where polymer/PCBM has no absorption, which makes this device suitable for application in stacking devices to make full use of the solar spectrum. This device fabrication method has many advantages over the regular procedure. First of all, no thermal evaporation process is involved in the process, and each layer is coated by a low-cost and easy solution process. Second, in contrast to the reactive metal cathode in regular devices, the cathode in C O M M U N IC A IO N

Conducting polymer gas sensors

Abstract: Recent results with solid-state semiconductor gas sensors based on organic sensor elements are reviewed. Devices based on metal phthalocyanines show useful responses to NO2. Lead phthalocyanine combines the highest conductivity with the maximum sensitivity to NO2. A thin-film lead phthalocyanine sensor has successfully been used to monitor NOx produced by shot-firing in coal mines. To obtain reasonable conductance and speed of response and recovery, phthalocyanine sensors have been operated at 170°C. Conducting polymer materials, and particularly chemically doped polypyrrole, show responses to toxic gases at ambient temperature. Initial work, using polypyrrole black impregnated filter paper, showed a response to ammonia. More recently, using polypyrrole films electrochemically deposited over electrode arrays, responses to nitrogen dioxide and hydrogen sulphide have also been obtained. Organic-semiconductor gas sensors may have advantages compared to metal-oxide devices in their sensitivity to toxic gases and in their ability to operate at or near room temperature. However, the mechanisms of device function are not yet well understood.