Improved thermoelectric performance of PEDOT:PSS/Bi2Te3/reduced graphene oxide ternary composite films for energy harvesting applications

• Published in: RSC advances 2024-10, Vol.14 (47), p.34883-34892
• Main Authors: Rathi, Vaishali, Singh, Kamal, Parmar, K P S, Brajpuriya, Ranjeet K, Kumar, Ashish
• Format: Article
• Language: English
• Subjects: Carrier mobility; Current carriers; Electrical resistivity; Energy harvesting; Graphene; Maximum power; Power factor; Raman spectroscopy; Room temperature; Seebeck effect; Spin coating; Temperature gradients; Thermal conductivity; Thermoelectric generators; Thermoelectric materials; X ray photoelectron spectroscopy
• ISSN: 2046-2069; 2046-2069
• DOI: 10.1039/d4ra06184e

We report a significant enhancement in the thermoelectric power of PEDOT by fabricating a novel ternary composite film by incorporating Bi2Te3 and rGO. A series of five samples of PEDOT:PSS/Bi2Te3/rGO ternary composite films were synthesized using a spin coating method and having different weight% (0.0, 0.1, 0.2, 0.3 wt%) of rGO in PEDOT:PSS/0.4 wt% Bi2Te3 mixture along with pure PEDOT:PSS sample. The Seebeck coefficient, electrical conductivity, and power factor increased in composite films compared to pure PEDOT:PSS films. Incorporating rGO enhanced charge carrier mobility because of its highly conductive network, whereas Bi2Te3 provided higher Seebeck coefficients owing to its inherent thermoelectric properties. PEDOT:PSS offered mechanical flexibility and a conductive matrix, facilitating effective phonon scattering and inherently lower thermal conductivity. The sample (PEDOT:PSS/0.4 wt% Bi2Te3/0.1 rGO wt%) demonstrated the highest electrical conductivity of 1522.4 S cm−1, a Seebeck coefficient of (+) 24.7 μV K−1, and a power factor of 93.16 μW m−1 K−2 at room temperature. These values represent a twelve-fold increase compared to pristine PEDOT films. A flexible, printable thermoelectric generator (TEG) was also demonstrated on polyimide substrate using inks prepared from p-type PEDOT:PSS/Bi2Te3/rGO and n-type PVDF/Ni NWs. The paper TEG achieved a maximum power output of 242.1 nW, with an output voltage of 9.84 mV and an output current of 49.21 μA at a temperature difference (ΔT) of 35 K. XRD, Raman spectroscopy SEM, and XPS techniques were used to understand the underlying mechanism. This novel PEDOT:PSS/Bi2Te3/rGO ternary composite film significantly outperforms previously reported organic thermoelectric materials. The results indicate that the combined effect of PEDOT:PSS, Bi2Te3, and rGO greatly enhances thermoelectric performance, offering a promising and efficient route for the application of PEDOT in advanced thermoelectric conversion processes.