Enhanced mobility and controlled transparency in multilayered reduced graphene oxide quantum dots: a charge transport study

Author(s)

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

Affiliation

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

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

^[3] Univ Strasbourg, CNRS, ISIS UMR 7006, 8 Allee Gaspard Monge, F-67000 Strasbourg - France

^[4] Ctr Univ Cent Paulista UNICEP, BR-13563470 Sao Carlos, SP - Brazil

^[5] Univ Sao Paulo, IFSC, BR-13560250 Sao Carlos, SP - Brazil

^[6] Univ Fed Ceara, Dept Phys, BR-60440900 Fortaleza, Ceara - Brazil

• Document type: Journal article
• Source: Nanotechnology; v. 30, n. 27 JUL 5 2019.
• Web of Science Citations: 2

Abstract

Reduced graphene oxide (rGO) layers are known to be significantly conductive along the basal plane throughout delocalized sp(2) domains Defects present in rGO implies in disordered systems with numerous localized sites, resulting in a charge transport governed mainly by a 2D variable range hopping (VRH) mechanism These characteristics are observed even in multilayered rGO since the through-plane conduction is expected to be insubstantial. Here, we report on the multilayer assembly of functionalized rGO quantum dots (GQDs) presenting 3D VRH transport that endows elevated charge carrier mobility, ca similar to 236 cm(2) V(-1 )s(-1). Polyelectrolyte-wrapped GQDs were assembled by layer-by-layer technique (LbL), ensuring molecular level thickness control for the formed nanostructures, along with the adjustment of the film transparency (up to 92% in the visible region). The small size and the random distribution of GQDs in the LbL structure are believed to overcome the translational disorder in multilayered films, contributing to a 3D interlayer conduction that enhances the electronic properties. Such high-mobility, transparency-tunable films assembled by a cost-effective method possess interesting features and wide applicability in optoelectronics. (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