Charge carrier transport in defective reduced graphene oxide as quantum dots and nanoplatelets in multilayer films

Author(s)

Jimenez, Mawin J. M. ^[1] ; Oliveira, Rafael F. ^[2] ; Almeida, Tiago P. ^{[3, 4]} ; Hensel Ferreira, Rafael C. ^[1] ; Bufon, Carlos Cesar B. ^[2] ; Rodrigues, Varlei ^[1] ; Pereira-da-Silva, Marcelo A. ^{[5, 6]} ; Gobbi, Angelo L. ^[2] ; Piazzetta, Maria H. O. ^[2] ; Riul, Jr., Antonio ^[1]

Affiliation

^[1] Univ Estadual Campinas, UNICAMP, Gleb Wataghin Inst Phys, Dept Appl Phys, BR-13083970 Campinas, SP - Brazil

^[2] Brazilian Ctr Res Energy & Mat CNPEM, Brazilian Nanotechnol Natl Lab LNNano, BR-13083970 Campinas, SP - Brazil

^[3] Univ Estadual Campinas, PhD Program Bionergy, BR-13083862 Campinas, SP - Brazil

^[4] Delft Univ Technol, Dept Biotechnol, Dept Biotechnol Biocatalysis, Van der Maasweg 9, NL-2629 HZ Delft - Netherlands

^[5] Ctr Univ Cent Paulista UNICEP, BR-13563470 Sao Carlos, SP - Brazil

^[6] Univ Sao Paulo, IFSC, BR-13560250 Sao Carlos, SP - Brazil

• Document type: Journal article
• Source: Nanotechnology; v. 28, n. 49 DEC 8 2017.
• Web of Science Citations: 4

Abstract

Graphene is a breakthrough 2D material due to its unique mechanical, electrical, and thermal properties, with considerable responsiveness in real applications. However, the coverage of large areas with pristine graphene is a challenge and graphene derivatives have been alternatively exploited to produce hybrid and composite materials that allow for new developments, considering also the handling of large areas using distinct methodologies. For electronic applications there is significant interest in the investigation of the electrical properties of graphene derivatives and related composites to determine whether the characteristic 2D charge transport of pristine graphene is preserved. Here, we report a systematic study of the charge transport mechanisms of reduced graphene oxide chemically functionalized with sodium polystyrene sulfonate (PSS), named as GPSS. GPSS was produced either as quantum dots (QDs) or nanoplatelets (NPLs), being further nanostructured with poly(diallyldimethylammonium chloride) through the layer-by-layer (LbL) assembly to produce graphene nanocomposites with molecular level control. Current-voltage (I-V) measurements indicated a meticulous growth of the LbL nanostructures onto gold interdigitated electrodes (IDEs), with a space-charge-limited current dominated by a Mott-variable range hopping mechanism. A 2D intra-planar conduction within the GPSS nanostructure was observed, which resulted in effective charge carrier mobility (mu) of 4.7 cm(2) V-1 s(-1) for the QDs and 34.7 cm(2) V-1 s(-1) for the NPLs. The LbL assemblies together with the dimension of the materials (QDs or NPLs) were favorably used for the fine tuning and control of the charge carrier mobility inside the LbL nanostructures. Such 2D charge conduction mechanism and high ae values inside an interlocked multilayered assembly containing graphene-based nanocomposites are of great interest for organic devices and functionalization of interfaces. (AU)

• FAPESP's process: 14/25979-2 - Fabrication and characterization of devices and systems based on hybrid nanomembranes
• Grantee: Carlos César Bof Bufon
• Support Opportunities: Research Grants - Young Investigators Grants
• FAPESP's process: 14/03691-7 - Fabrication of microfluidic devices envisanging aplications in precision agriculture and bioenergy
• Grantee: Antonio Riul Júnior
• Support Opportunities: Program for Research on Bioenergy (BIOEN) - Regular Program Grants