Fig. 1. Thermoelectric performance of PEDOT-Tos-PPP films after post-treatment with different concentrations of VC aqueous solution at room temperature (295 K).

Fig. 2. Thermoelectric stability of PEDOT-Tos-PPP film in air after treatment with 20% VC aqueous solution.

Fig. 3. The relationship between (a) conductivity, (b) Seebeck coefficient, and (c) power factor with temperature in untreated and 20% VC aqueous solution in air for 2 d. The inset in Fig. (a) is the relations between ln(σ) and T^–1/3.

Fig. 4. UV-Vis-NIR spectra of untreated, VC post-treated fresh samples and post-treated samples in air for a period of time.

Fig. 5. XPS of PEDOT-Tos-PPP film prepared by the VPP method, fresh samples after VC post-treatment, and post-treated samples in the air for a period of time: (a) Survey spectrum; (b) S_2p spectrum; (c) C_1s spectrum; (d) O_1s spectrum.

Fig. 6. Raman of untreated PEDOT-Tos-PPP films and films after treatment with different concentrations of VC aqueous solution.

Fig. 7. FESEM of (a) PEDOT-Tos-PPP film prepared by VPP method, (b) fresh sample after VC post-treatment, and (c) post-treated sample in the air for a period of time.