Conducting Polymers—Modern Semiconductors: A Theoretical Overview (original) (raw)

First-principles studies of some conducting polymers: PPP, PPy, PPV, PPyV, and PANI

Journal of Molecular Structure-Theochem, 1999

We present results of first-principles calculations of the electronic properties of several conducting polymers containing either phenylene or pyridine rings. The applied density functional method employs linear muffin-tin orbitals (LMTOs) as basis functions. It has been explicitly constructed for calculating the electronic properties of infinite, periodic, helical, polymeric chains. We study poly(p-phenylene) (PPP), poly(p-phenylenevinylene) (PPV), poly(2,5-pyridine) (PPy), poly(2,5-pyridinevinylene) (PPyV) and polyaniline (PANI). The structural parameters were obtained either from experimental information or by applying semi-empirical methods. We find that by replacing a carbon atom by a nitrogen atom in the phenylene ring, an occupied n-band appears. Simultaneously, the first ionization potential is increased which can be related to the electronegativity of nitrogen compared to that of carbon. When a vinylene linkage separates the rings, steric effects between the rings are diminished and the rings may thus be coplanar. This increases the p -electron delocalization and produces a stabilization of the system. In contrast, by replacing the vinylene linkage by an amine group (resulting in PANI) a non-planar polymer is obtained which has a larger band gap and a smaller ionization potential. ᭧ Journal of Molecular Structure (Theochem) 468 (1999) 181-191 0166-1280/99/$ -see front matter ᭧ Fig. 1. Schematic representation of the unit cell of the studied polymers.

Advances in conductive polymers

European Polymer Journal, 1998

AbstractÐConductive polymers are a new class of materials which exhibit highly reversible redox behaviour and the unusual combination of properties of metal and plastics. The prospective utility of conductive polymers with a potent application in number of growing technologies in biomolecular electronics, telecommunication, display devices and electrochemical storage systems, etc. has further enhanced the interest of researchers in this novel area. An eort has been made in this article to present an updated review on the various aspects of conductive polymers, viz. synthesis of conductive polymers, doping, structure analysis and proposed utility for further study of the future scienti®c and technological developments in the ®eld of conductive polymers. #

Conducting Polymers and their Applications

Current Physical Chemistrye, 2012

This review article focuses on conducting polymers and their applications. Conducting polymers (CPs) are an exciting new class of electronic materials, which have attracted an increasing interest since their discovery in 1977. They have many advantages, as compared to the non-conducting polymers, which is primarily due to their electronic and optic properties. Also, they have been used in artificial muscles, fabrication of electronic device, solar energy conversion, rechargeable batteries, and sensors. This study comprises two main parts of investigation. The first focuses conducting polymers (polythiophene, polyparaphenylene vinylene, polycarbazole, polyaniline, and polypyrrole). The second regards their applications, such as Supercapacitors, Light emitting diodes (LEDs), Solar cells, Field effect transistor (FET), and Biosensors. Both parts have been concluded and summarized with recent reviewed 233 references.

Conducting Polymers: Concepts and Applications

Journal of Atomic, Molecular, Condensate and Nano Physics, 2018

The developments in the field of electrically conducting polymers have grown very rapidly since the discovery and there is a very sharp increase in conductivity when intrinsically insulating organic conjugated polymers are doped with oxidizing and reducing agents. An overview of technological developments involving conducting polymers clearly indicates that the field expands at unprecedented rates. The manuscript first introduces the conducting polymers (CPs), conducting mechanism, concepts of doping and briefly introduces main applications. Different types of CPs, their unique properties and synthesis is discussed. The present review will help the effective implementation of conducting polymers in different fields, which directly depends on the degree of understanding of their behaviour and properties.

ELECTRICAL PROPERTIES OF POLYMERS (1)

The processability and film-forming properties of the conjugated polymers are crucial for the fabrication of high-performance photoluminescence emitting diodes (PLEDs) and polymer solar cells (PSCs). However, conjugated polymers of poly(p-phenylene vinylene) (PPV), polytheiophene (PT), polypropylene (PPP), etc. without substituted side chains are insoluble and infusible, which limits their application.

Tuning of Electronic Properties in Conducting Polymers

Collection of Czechoslovak Chemical Communications, 2001

Structural and electronic transitions in poly(thiophenyleneiminophenylene), usually referred to as poly(phenylenesulfidephenyleneamine) (PPSA) upon electrochemical doping with LiClO4 have been investigated. The unusual electrochemical behavior of PPSA indicates that the dopant anions are bound in two energetically different sites. In the so-called "binding site", the ClO4- anion is Coulombically attracted to the positively charged S or N sites on one chain and simultaneously hydrogen-bonded with the N-H group on a neighboring polymer chain. This strong interaction causes a re-organization of the polymer chains, resulting in the formation of a networked structure linked together by these ClO4- Coulombic/hydrogen bonding "bridges". However, in the "non-binding site", the ClO4- anion is very weakly bound, involves only the electrostatic interaction and can be reversibly exchanged when the doped polymer is reduced. In the repeated cycling, the continuous an...