Flexible polymer substrates poly

Solar cells can directly convert solar energy into electricity, which is clean and inexhaustible. Generally, the solar cells are built with a planar sandwiched structure on the rigid substrate, which restricts their applications in many fields. Flexible polymer substrates, such as poly(ethyleneterephthalate) (PET), poly(ethylenenaphthalate) (PEN), and polydimeth-ylsiloxane (PDMS), have been widely used to fabricate flexible solar cells. With high stability and flexibility, the solar cells can easily integrate with other portable or wearable devices to significantly extend their applications. 

A thin film ( 100 nm) of a PPV derivative is sandwiched between two electrodes supported on a solid substrate, such as glass, a flexible plastic substrate, such as poly(propylene), or even a thin film of aluminium, see Figure 6.1. The device substrate provides the mechanical support to the anode, electroluminescent polymer layer and the cathode. The anode is transparent in... 

Organic photoreceptors can be prepared in either a flexible web or drum format. Webs are usually prepared on polymer substrates, polyethylene tere-phthalate being the most common. The substrates are between 100 to 200 pm in thickness and coated with a conducting surface layer. The substrates often contain layers on the reverse side for reduced curl, static discharge prevention, and control of frictional characteristics. The web configuration is also widely used for laboratory studies. For drums, the substrate is a metal cylinder, usually Al. Recently, however, drums of a poly(phenylene sulfide) resin doped with conductive C black have been developed (Kawata and Hikima, 1996). Drums are widely used in low- and mid-volume applications. Drums, however, are not well suited for research purposes. Thus, the preparation and characterization of drum photoreceptors is usually related to a specific application. 

In another work, shear-induced stretching of relatively flexible positively charged poly[methacryloylojqrethyl-dimethyl-(3-pyirol-l-yl-propyl) ammonium bromide] (PME-D-AB) chains adsorbed on a planar substrate (mica) was explored by AFM and Brownian dynamics computer simulations by Stamm s and Lowen s groups. Considerably sttetched polymer chains along the shear flow with a wealth of different individual shapes were found (Figure 12). 

Having a complete functional textile solar cell motivates the researchers to attempt an approach for direct incorporation of photovoltaic cell elements onto the textile. The textile substrates inherently scatter most part of the incident light outward. Therefore, it was found necessary to apply a layer of the very flexible polymer PE onto the textile substrate to have a surface compatible with a layered device. The textile-PE substrate was plasma treated before application of the transparent PEDOT electrode in order to obtain good adhesion of the PEDOT layer to the PE carrier. Then screen-printing was employed for the application of the active polymer poly[2-methoxy-5-(2 -ethylhexyloxy)-p-phenylene vinylene] (MEH-PPV) [33]. 

FIGURE 17.15 Direct electrochemical contact between an incoming AFM-SECM probe and the redox Fc heads of nanometer-sized, flexible chains (such as PEG or DNA), end-grafted onto an electrode substrate. The Fc heads are alternatively oxidized at the tip and reduced back at the substrate. For clarity, the tip is not drawn to scale. The chains are pictured in the mushroom conformation. (Adapted with permission from Abbou, J., Anne, A., and Demaille, C., Probing the structure and dynamics of end-grafted flexible polymer chain layers by combined atomic force—Electrochemical microscopy. Cyclic voltammetry within nanometer-thick macromolecular poly(ethylene glycol) layers, J. Am. Chem. Soc., 126,10095-10108, 2004. Copyright 2004 American Chemical Society.)... 

Flexible printed wiring laminates usually contain (but are not limited to) either a polyimide or a polyester [usually poly(ethylene terephthalate)] with copper conductors. These laminates are prepared in sheets or by roll-to-roll lamination, usually by means of an adhesive. Alternatively, direct fusion without an adhesive is used. Recent developments include the use of alternative substrate materials such as poly(ether sulfones), additive plating of copper, and casting of a polymer directly on the copper foil web. 

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