A facile preparation route of n-type carbon buckypaper and its enhanced thermoelectric performance

In this study, we prepared a thermoelectric device with p-type organic thermoelectric hybrid film and n-type buckypaper. Both the film and buckypaper are made of a hybrid filler of graphite nanoplatelets (GNPs) and single-walled carbon nanotubes (SWNTs). The p-type thermoelectric hybrid film has a free-standing form and enhanced thermoelectric performance owing to a polyvinylidene fluoride/carbon hybrid film purified with an acid solution, which successfully eliminates amorphous carbon, additives, and impurities. The n-type thermoelectric buckypaper was made with a filtration method with GNPs and SWNTs to the membrane filter. To convert this to an n-type thermoelectric property, a polyethyleneimine solution was also added by filtration process. In addition, adding sodium dodecyl benzene sulfonate during carbon dispersion enhanced thermoelectric performance, which was confirmed by measuring the electrical conductivity and Seebeck coefficient. A thermoelectric device using silver electrodes was produced with the thermoelectric composite film and buckypaper to verify its thermoelectric voltage and generating power.