Semiconducting conjugated polymers

The purpose of this chapter is to illustrate the type of information that can be obtained about organic conjugated polymers, semiconducting and conducting, through the use of photoelectron spectroscopic measurements. Thus it presents a background to the application of photoelectron spectroscopy for conducting poly-... 

Polymers. The Tt-conjugated polymers used in semiconducting appHcations are usually insulating, with semiconducting or metallic properties induced by doping (see Flectrically conductive polymers). Most of the polymers of this type can be prepared by standard methods. The increasing use of polymers in devices in the last decade has led to a great deal of study to improve the processabiUty of thin films of commonly used polymers. 

Polymers, large molecules made up of smaller molecules in a repeating pattern, are used for many electrochromic materials. Conjugating polymers, which have alternating single and double bonds, are particularly suitable. Figure B shows the electrochemical oxidation of the conjugated polymer, polythiophene. Oxidation (in which electrons are removed) produces a semiconductive polymer. The neutral (unoxidized) polythiophene is red in color, whereas the semiconductive polythiophene (oxidized) is blue. In their neutral... 

Despite the scientific progress and the demonstration of novel device concepts, there was considerable skepticism that semiconducting polymers would ever reach the levels of purity required for long-lifetime commercial devices. In the context of the last 50 years of semiconductor physics, conjugated polymers were often... 

The introduction of bulky side chains that contain adamantyl groups to poly(p-phenylenevinylene) (PPV), a semiconducting conjugated polymer, decreases the number of interchain interactions. This action will reduce the aggregation quenching and polymer photoluminescence properties would be improved [93]. 

Section 1.2 gives a brief review of conjugated polymers in semiconducting and metallic phases. Section 1.3 discusses device architectures and their corresponding processes. Section 1.4 introduces some novel devices and their functions in thin-film polymer devices. Section 1.5 is devoted to technical merits of SMOLEDs and PLEDs used as emitter elements in flat-panel displays. 

Polymer laser diodes have been an attractive topic after the discovery of EL in conjugated polymers. Optical lasing in semiconducting luminescent polymer solutions was first... 

MD McGehee and AJ Heeger, Semiconducting (conjugated) polymers as materials for solid-state... 

X. Zhang and S.A. Jenekhe, Electroluminescence of multicomponent conjugated polymers. 1. Roles of polymer/polymer interfaces in emission enhancement and voltage-tunable multicolor emission in semiconducting polymer/polymer heterojunction, Macromolecules, 33 2069-2082, 2000. 

U.S. 5,425,125 Optical device incorporating semiconductive conjugated polymer... 

Approach of Treating Charge Carriers in Semiconducting Conjugated Polymers... 

Warman JM, de Haas MP, Dicker G, Grozema FC, Ptris J, Debije MG (2004) Charge mobilities in organic semiconducting materials determined by pulse-radiolysis time-resolved microwave conductivity 7c-bond-conjugated polymers versus tc—tc-stacked discotics. Chem Mater 16 4600... 

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