Thermoelectric properties of nanocomposite thin films prepared with poly(3,4-ethylenedioxythiophene) poly(styrenesulfonate) and graphene.
Carbon nanotubes (CNTs), either single wall carbon nanotubes (SWNTs) or multiwall carbon nanotubes (MWNTs), can improve the thermoelectric properties of poly(3,4-ethylenedioxythiophene) poly(styrenesulfonate) (PEDOT : PSS), but it requires addition of 30-40 wt% CNTs. We report that the figure of merit (ZT) value of PEDOT : PSS thin film for thermoelectric property is increased about 10 times by incorporating 2 wt% of graphene. PEDOT : PSS thin films containing 1, 2, 3 wt% graphene are prepared by solution spin coating method. X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy analyses identified the strong π-π interactions which facilitated the dispersion between graphene and PEDOT : PSS. The uniformly distributed graphene increased the interfacial area by 2-10 times as compared with CNT based on the same weight. The power factor and ZT value of PEDOT : PSS thin film containing 2 wt% graphene was 11.09 μW mK(-2) and 2.1 × 10(-2), respectively. This enhancement arises from the facilitated carrier transfer between PEDOT : PSS and graphene as well as the high electron mobility of graphene (200,000 cm(2) V(-1) s(-1)). Furthermore the porous structure of the thin film decreases the thermal conductivity resulting in a high ZT value, which is higher by 20% than that for a PEDOT : PSS thin film containing 35 wt% SWNTs.
Department of Chemical & Biomolecular Engineering (BK21), Center for Ultramicrochemical Process Systems (CUPS), Graduate School of EEWS (WCU), Korea Advanced Institute of Science and Technology, 335 Gwahangno, Yuseong-gu, Daejeon 305-701, Republic of Korea.
Gil Ho
GH
Kim
Deok Hyun
DH
Hwang
Seong Ihl
SI
Woo
D006108:Graphite / Q000737:chemistry*; D008567:Membranes, Artificial; D053761:Nanocomposites / Q000737:chemistry*; D037742:Nanotubes, Carbon / Q000737:chemistry*; D011137:Polystyrenes / Q000737:chemistry*; D013696:Temperature; D013876:Thiophenes / Q000737:chemistry*
D008567:Membranes, Artificial; D037742:Nanotubes, Carbon; D011137:Polystyrenes; D013876:Thiophenes; C533756:poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate); D006108:Graphite