Thermoelectric Properties Of PEDOT:PSS Enhanced By Carbon Materials

Among polymer thermoelectric materials,PEDOT:PSS has good film formation,easy processing performance and other advantages,which made it to be a hot spot for people to study.Graphene oxide(GO),reduced graphene oxide(RGO),graphene quantum dots(GQDs),and single-walled carbon nanotubes(SWCNTs)have a large number of ?electrons that can occur ?-? conjugation with PEDOT:PSS,which will change the arrangement of polymer chains in the PEDOT:PSS matrix,and then enhance the thermoelectric properties of PEDOT:PSS.The specific jobs of this paper are listed as follows:(1)GO,RGO and GQDs were added to the PEDOT:PSS solution to prepared PEDOT:PSS/GO,PEDOT:PSS/RGO and PEDOT:PSS/GQDs composite films,respectively.The effects of three fillers on the microstructure and thermoelectric properties to PEDOT:PSS matrix were studied.The results show that GQDs have the best performance in enhancing the thermoelectric properties of PEDOT:PSS materials,and GO performance is the worst.When the mass ratio of PEDOT:PSS to GQDs is 100:15,the PEDOT:PSS/GQDs film(P-G-15)has the best thermoelectric performance.When the temperature is 310 K,compared with the pure PEDOT:PSS film,the electrical conductivity,Seebeck coefficient,and P increased by 31%,121%,550%,respectively.(2)In this paper,SWCNTs was introduced into PEDOT:PSS materials to prepare PEDOT:PSS/SWCNTs composite films with different mass ratios.And then the microstructure and thermoelectric properties of the films were studied.The results show that: When the mass ratio of PEDOT:PSS to SWCNTs is 100:6,the PEDOT:PSS/SWCNTs composite film(P-S-6)has the best thermoelectric performance.When the temperature is310 K,compared with the pure PEDOT:PSS film,the conductivity,Seebeck coefficient,and P increased by 81%,124%,and 854%,respectively.(3)In order to solve the problems of the low conductivity of GQDs and the poor dispersion of SWCNTs in water,GQDs/SWCNTs hybrids were prepared,which have excellent dispersion in water because of the conjugation of GQDs and SWCNTs.Finally,the SWCNTs/GQDs hybrids were introduced into PEDOT:PSS,and the preparedPEDOT:PSS/SWCNTs/GQDs composite films have excellent thermoelectric properties.The experimental results show that: when the mass ratio of PEDOT:PSS,GQDs and SWCNTs is 100:10:6,the thermoelectric properties of the composite films(P-G-S-10-6)are the best in the experiment range.When the temperature is 310 K,the conductivity,P-G-S-10-6 film's conductivity,Seebeck coefficient and P respectively increased by 17%,161%,681% compared with the pure PEDOT:PSS film.The performance of SWCNTs/GQDs is not as good as that of SWCNTs in terms of enhanced material conductivity and PF.However,due to the simultaneous presence of SWCNTs and GQDs,the P-G-S-10-6 film has the highest Seebeck coefficient in all composite films,which has certain reference value and guidance significance for the future research of thermoelectric materials.In addition,the proper mass ratio is very important in the preparation of GQDS/SWCNTs hybrids.Otherwise,excess GQDs or SWCNTs will disturb the interaction between GQDS/SWCNTs hybrid and PEDOT:PSS,which will lead to a decrease in the conductivity of films and prevent the improvement of thermoelectric performance.