Photovoltaics, electrically active polymers

Miniaturization, nanocomposites, nanotubes, nanopolymers used as vectors for active ingredients, micro-processors and photovoltaic cells based on electrically conducting polymers plastics are each time veetors of news. Sinee their origin, they have constantly revolutionized the way we live, whether it is in terms of comfort, safety, health, communication, transportation, architecture, design, sports or leisure. 

This section describes the use of oligomer films as active media and demonstrates the importance of the film morphology to both the electrical and the optical properties. This is a factor which has hardly received any attention until now, but one which certainly deserves consideration, for polymers as well. The crucial importance of the microslructurc is equally demonstrated by studies of the photovoltaic effect 1118J this topic will not be dealt with here. 

The absence of solvents in such solid-polymer-electrolyte photovoltaic cells presents the possibility of fabricating corrosion-free systems. The thin-film solid-state cells also allow fabrication of multispectral cells composed of more than one semiconductor in optical and electrical series. A solid-state photovoltaic cell, n-Si/Pt/PP/PEO(K.I/ l2)/Pt/ITO, was studied. The surface modifications of n-Si with PP can dramatically reduce the large activation energy barrier against efficient charge transfer between semiconductor and polymer-solid electrolyte. The efficiency of this cell is limited by a high surface recombination velocity associated with surface states of the n-Si. The cell had V = 225 mV and 11 niA cm at 100 mW cm illumination with junction ideality factor of 1.5. This implies the existence of deleterious surface states acting as recombination centres. 

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