Thermoelectric properties and intrinsic conduction processes in DBSA and NaSIPA doped polyanilines

• Published in: Synthetic metals Vol. 243; pp. 44 - 50
• Main Authors: Horta-Romarís, Laura, González-Rodríguez, M. Victoria, Lasagabáster, Aurora, Rivadulla, Francisco, Abad, María-José
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier B.V 01.09.2018; Elsevier BV
• Subjects: Carrier density; Charge density; Chemical synthesis; Conducting polymers; Conductivity; Current carriers; Doping; Electrical conductivity; Electrical resistivity; Hopping conduction; Nanorods; Polyaniline; Polyanilines; Polymers; Seebeck coefficient; Seebeck effect; Semiconductors; Sodium dodecylbenzenesulfonate; Sodium salts; Thermoelectrical properties; Thermoelectricity; Conducting polymers; Seebeck coefficient; Electrical conductivity; Thermoelectrical properties; Polyaniline
• ISSN: 0379-6779; 1879-3290
• DOI: 10.1016/j.synthmet.2018.06.002

[Display omitted] •PANI-DBSA high doping and layer structure lead to low constant Seebeck coefficient.•Poor doping and low crystallinity explain high Seebeck coefficients of PANI-NaSIPA.•PANI-NaSIPA 0.5 M ZT is two orders of magnitude higher than that of PANI-DBSA 0.5 M.•For PANI-DBSA, the carrier transport follows a hopping behavior (hole type).•PANI-NaSIPA shows a diffusive regimen, usual of degenerate metallic semiconductors. Seeking to gain fundamental understanding of the thermoelectric (TE) behavior of polyanilines (PANIs), structure- property relationships of PANI nanorods, doped with dodecylbenzenesulfonic acid (DBSA) and 5-sulfoisophtalic acid sodium salt (NaSIPA), and prepared by an indirect synthetic route, are discussed in terms of the contribution of the acid concentrations on the thermoelectric properties. The synergistic combination of high doping level and layer structure, accounts for the moderately high electrical conductivities (σ) and low constant Seebeck coefficients (α) of PANI-DBSA. Conversely, the poor doping ability of NaSIPA and low crystallinity degree explain the low electrical conductivities along with significant increases in Seebeck coefficient values. In relation to conduction mechanisms, PANI-DBSA shows a hopping behavior with a carrier concentration of c≈0.49 (hole type), while PANI-NaSIPA displays a diffusive regime, characteristic of degenerate metallic semiconductors, with an estimated charge carrier density of n ≈3 × 1021 e/cm3.