The role of charge transfer at reduced graphene oxide/organic semiconductor interface on the charge transport properties
Journal article, 2019

The effect of 1-pyrenesulfonicacid sodium salt (1-PSA), tetracyanoethylene (TCNE) and tetrafluoro-tetracyanoquinodimethane (F4-TCNQ) on charge transport properties of reduced graphene oxide (RGO) is examined by measuring the transfer characteristics of field-effect transistors and co-planar time-of-flight photocurrent technique. Evidence of p-type doping and a reduction of mobility of electrons in RGO upon deposition of these materials is observed. Time-resolved photocurrent measurements show a reduction in electron mobility even at submonolayer coverage of these materials. The variation of transit time with different coverages reveals that electron mobility decreases with increasing the surface coverage of 1-PSA, TCNE and F4-TCNQ to a certain extent, while at higher coverage the electron mobility is slightly recovered. All three molecules show the same trend in charge carrier mobility variation with coverage, but with different magnitude. Among all three molecules, 1-PSA acts as weak electron acceptor compared to TCNE and F4-TCNQ. The additional fluorine moieties in F4-TCNQ provides excellent electron withdrawing capability compared to TCNE. The experimental results are consistent with the density functional theory calculations.

Charge transport

Organic thin film transistors

Organic semiconductors

Graphene oxide

Time of flight photoconductivity

Author

Srinivasa Rao Pathipati

Vignans Foundation for Science Technology and Research University

Egon Pavlica

University of Nova Gorica

E. Treossi

Istituto per la Sintesi Organica e la Fotoreattività

Vincenzo Palermo

Istituto per la Sintesi Organica e la Fotoreattività

Chalmers, Industrial and Materials Science, Materials and manufacture

Gvido Bratina

University of Nova Gorica

Organic Electronics: physics, materials, applications

1566-1199 (ISSN)

Vol. 77 105499

Subject Categories

Inorganic Chemistry

Materials Chemistry

Condensed Matter Physics

DOI

10.1016/j.orgel.2019.105499

More information

Latest update

10/6/2020