Negative differential resistance and sample conductivity in polypyrrole films

• Published in: Synthetic metals Vol. 156; no. 16; pp. 1083 - 1089
• Main Authors: Gomis, V., Bellver, D., Ferrer-Anglada, N., Ribó, J.M., El-Hachemi, Z., Movaghar, B.
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier B.V 01.08.2006; Amsterdam Elsevier Science; New York, NY
• Subjects: Applied sciences; Conducting polymer; Electrical conductivity; Electrical, magnetic and optical properties; Exact sciences and technology; Metal–insulator phase transition; Organic polymers; Physicochemistry of polymers; Polypyrrole; Properties and characterization; Electrical conductivity; Conducting polymer; Polypyrrole; Metal–insulator phase transition; Electrical properties; Voltage current curve; Experimental study; Modeling; Sulfonate; Conducting polymers; Phenomenological model; Metal insulator transition; Doped polymer; Electric field effect; Metal-insulator phase transition; Pyrrole polymer
• ISSN: 0379-6779; 1879-3290
• DOI: 10.1016/j.synthmet.2006.07.001

An unusual negative differential resistance (NDR) has been observed in I– V response in p-toluensulfonate-doped polypyrrole films, leading to a conductivity switching effect of almost four orders of magnitude. The effect appears at temperatures below 20 K for highly conducting samples while it is displaced to temperatures close to the room temperature for more resistive samples. The observed correlation between conductivity and switching phenomenon provides a fingerprint of the influence played by the sample nanostructure. The relation between the chemical structure of the material and the observed physical phenomenon is discussed.