Synergistic effect of graphene oxide on structural and electrical performance of PEDOT:PSS polymer

• Published in: Materials today : proceedings Vol. 82; pp. 375 - 380
• Main Authors: Sharma, Ruchi K., Sharma, Deepak, Saini, Anjali, Laxmi, Subha, Singh, B.P., Srivastava, Sanjay K.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 2023
• Subjects: Electrical conductivity; Graphene oxide; Hole transport layer; PEDOT:PSS; Hole transport layer; Graphene oxide; Electrical conductivity; PEDOT:PSS
• ISSN: 2214-7853; 2214-7853
• DOI: 10.1016/j.matpr.2023.03.114

PEDOT:PSS has emerged as the most attractive organic polymer based hole transport layer for optoelectronic device application. However, electrical conductivity of the pristine polymer is quite poor and needs to be improved by suitable secondary dopants. Graphene oxide (GO) is a promising dopant to improve the properties of the polymer. However, the subject needs to be explored further to understand the basic cause of the interaction between PEDOT:PSS and GO and so the electrical conductivity (σ). In the present study, significantly improved electrical conductivity of the polymer via GO addition is reported without compromising its optical transparency. Synthesis of GO was achieved via modified Hummer’s method involving oxidation and intercalation of graphite interlayers. The high-quality GO flakes were obtained as confirmed by XRD, Raman spectroscopy, FTIR and UV–vis-NIR results. Further, PEDOT:PSS:GO composite was prepared via adding a small concentration of aqueous GO solution in the pristine PEDOT:PSS. The value of σ increased > 2 folds (∼327 to 712 S/cm) for 0.01 wt% GO blend in the composite solution. The improved electrical performance of PEDOT:PSS was further investigated at molecular level by Raman spectroscopy to understand the role of GO. The results revealed that the electrically neutral PEDOT:PSS network possibly transformed to linearly oriented electrically active oxidized PEDOT structure after GO addition, mainly supported by highly electronegative oxygen functional groups present in the GO. Such structural transformation led to the improved charge (holes) transportation in the composite layer. Therefore, PEDOT:PSS:GO could act as an efficient charge transport material in the development of optoelectronic devices including solar cells.