FisMat2017 - Submission - View

Abstract's title: Chemically synthesized Graphene Nanoribbon devices using graphene as the contact electrodes
Submitting author: Leonardo Martini
Affiliation: CNR-nano S3; università degli studi di Modena e Reggio Emilia
Affiliation Address: Via Giuseppe Campi, 213/a Dipartimento di Fisica
Country: Italy
Oral presentation/Poster (Author's request): Oral presentation
Other authors and affiliations: Zongping Chen(Max Planck Institute for Polymer Research, Ackermannweg 10, D-55128 Mainz, Germany), Neeraj Mishra(Max Planck Institute for Polymer Research, Ackermannweg 10, D-55128 Mainz, Germany), Akimitsu Narita(Max Planck Institute for Polymer Research, Ackermannweg 10, D-55128 Mainz, Germany), Klaus Müllen(Max Planck Institute for Polymer Research, Ackermannweg 10, D-55128 Mainz, Germany), Domenica Convertino(Center for NanotechnologyInnovation @ NEST, Istituto Italiano di Tecnologia, Piazza San Silvestro 12, 56127 Pisa, Italy), Camilla Coletti(Center for NanotechnologyInnovation @ NEST, Istituto Italiano di Tecnologia, Piazza San Silvestro 12, 56127 Pisa, Italy), Xinliang Feng(Center for Advancing Electronics Dresden (cfaed) & Department of Chemistry and Food Chemistry, TechnischeUniversität Dresden, 01062 Dresden, Germany), Marco Affronte(Dipartimento di Scienze Fisiche, Matematiche e Informatiche, Università di Modena e Reggio Emilia via G. Campi 213/A , 41125/A Modena. Italy), Andrea Candini(Centro S3, Istituto Nanoscienze - CNR, via G. Campi 213/A , 41125 Modena Italy)
Abstract

Graphene nano-Ribbons (GNRs) are one-dimensional strips of graphene where quantum confinement can open a direct bandgap. Combining the exceptional electrical properties of graphene with the one of semiconductor system represent a promising field for next generation of (opto-)electronics devices. GNRs can be fabricated in many ways, however, only bottom-up approaches offer the degree of control at the atomic level which is necessary to fully exploit their potentialities. In particular surface-assisted chemical synthesis allow to precisely fabricate GNR with well-defined size and morphology.

Here we demonstrate a novel concept of device, where chemically-synthesized GNRs are employed as the active channel and graphene as the electrodes. With respect to traditional metal contacts, the use of graphene offer the advantages of low-dimensionality and affinity with other carbon-based structures. In our devices, atomically-precise GNRs are synthesized by chemical vapor deposition on Au/mica substrate and then transferred on pre-fabricated graphene electrodes to act as active channel, avoiding any further fabrication step that could worsen the properties of the GNRs.

Firstly, we employed a continuous GNR layer as the device channel and graphene electrodes with gap sizes of few hundreds of nanometers, obtained by electron beam lithography.  We demonstrate field-effect transistor device with on/off current ratio as high as 104. [1]. Moreover, as we report, these devices are particularly appealing for opto-electronic applications and light sensors, because of their photoresponsivity as high as 6 x 105 A/W in the visible-UV range[2], orders of magnitude higher than pristine graphene. 

Finally, by employing the electroburning technique[3], we fabricate graphene electrodes with gaps in the range 10-50 nm; such gaps are suitable to contact individual or few GNRs. We report a systematic study using GNR with different morphologies (nanoribbons with armchair-type edges, AGNR, and different width N, where N = 5,9,10 being the integer number of Carbon atoms across the GNR width) corresponding to different electrical properties. We show that the electrical behavior of the devices is in qualitative agreement with the expected band-gap as calculated by theory.

The result we show demonstrates the huge potentiality of these all-graphene devices for novel application in nano-electronic, photonics and sensing.

[1] Zongping Chen et al., J. Am. Chem. Soc., 2016, 138 (47), pp 15488–15496.

[2] A. Candini et al., J. Phys. Chem. C, 2017, 121 (19), pp 10620–10625.

[3] Andrea Candini et al., Beilstein J. Nanotechnol. 2015, 6, 711–719.