TY - JOUR
T1 - Influence of chemical treatment on the electrical conductivity and thermopower of expanded graphite foils
AU - Rastegaralam, Mina
AU - Piao, Mingxing
AU - Kim, Gyutae
AU - Dettlaff-Weglikowska, Urszula
AU - Roth, Siegmar
PY - 2013/8
Y1 - 2013/8
N2 - We investigated the interaction of chemical materials with flexible graphite foils which were fabricated from the expanded graphite (EG) flakes by mechanical rolling and compressing. A variety of performed experiments demonstrated that the electrical conductivity and thermoelectric power (TEP) of the graphite foils can be modified by chemical treatments. In particular, the "as prepared" p-type graphite foil was successfully transferred into an n-type doped material upon a treatment with amine containing compounds. Generally, the acceptor-like chemicals increasing the concentration of the electric charge carriers enhanced the conductivity of the graphite foils, thereby, showing a decrease in the TEP reflected by the Seebeck coefficient, whereas the donor molecules significantly affected the conductivity and changed the sign and value of the TEP. Thermal and electrical insulating polymers, such as PVDF, PMMA, PVA, PS or PC, filling the inter-lamellar spacing reduced the conductivity of the foil due to increase of the layer-to-layer resistance. They also blocked heat flow in the foil, and consequently increased the Seebeck coefficient.
AB - We investigated the interaction of chemical materials with flexible graphite foils which were fabricated from the expanded graphite (EG) flakes by mechanical rolling and compressing. A variety of performed experiments demonstrated that the electrical conductivity and thermoelectric power (TEP) of the graphite foils can be modified by chemical treatments. In particular, the "as prepared" p-type graphite foil was successfully transferred into an n-type doped material upon a treatment with amine containing compounds. Generally, the acceptor-like chemicals increasing the concentration of the electric charge carriers enhanced the conductivity of the graphite foils, thereby, showing a decrease in the TEP reflected by the Seebeck coefficient, whereas the donor molecules significantly affected the conductivity and changed the sign and value of the TEP. Thermal and electrical insulating polymers, such as PVDF, PMMA, PVA, PS or PC, filling the inter-lamellar spacing reduced the conductivity of the foil due to increase of the layer-to-layer resistance. They also blocked heat flow in the foil, and consequently increased the Seebeck coefficient.
KW - Chemical treatment
KW - Electrical conductivity
KW - Expanded graphite
KW - Seebeck coefficient
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U2 - 10.1002/pssc.201200973
DO - 10.1002/pssc.201200973
M3 - Article
AN - SCOPUS:84881542424
SN - 1862-6351
VL - 10
SP - 1183
EP - 1187
JO - Physica Status Solidi (C) Current Topics in Solid State Physics
JF - Physica Status Solidi (C) Current Topics in Solid State Physics
IS - 7-8
ER -