Unravelling the Complete Raman Response of Graphene Nanoribbons Discerning the Signature of Edge Passivation

resumo

Controlling the edge morphology and terminations of graphene nanoribbons (GNR) allows tailoring their electronic properties and boosts their application potential. One way of making such structures is encapsulating them inside single-walled carbon nanotubes. Despite the versatility of Raman spectroscopy to resolve strong spectral signals of these systems, discerning the response of long nanoribbons from that of any residual precursor remaining outside after synthesis has been so far elusive. Here, the terrylene dye is used as precursor to make long and ultra-narrow armchair-edged GNR inside nanotubes. The alignment and characteristic length of terrylene encapsulated parallel to the tube's axis facilitates the ribbon formation via polymerization, with high stability up to 750 degrees C when the hybrid system is kept in high vacuum. A high temperature annealing is used to remove the terrylene external molecules and a subtraction model based on the determination of a scaling factor related to the G-band response of the system is developed. This not only represents a critical step forward toward the analysis of the nanoribbon-nanotube system, but it is a study that enables unraveling the Raman signatures of the individual CH-modes (the signature of edge passivation) for GNR for the first time with unprecedented detail.

palavras-chave

SEMICONDUCTING CARBON NANOTUBES; GROWTH; STATE; SIZE

categoria

Chemistry; Science & Technology - Other Topics; Materials Science

autores

Milotti, V; Berkmann, C; Laranjeira, J; Cui, WL; Cao, KC; Zhang, YF; Kaiser, U; Yanagi, K; Melle-Franco, M; Shi, L; Pichler, T; Ayala, P

Grupos

G6 - Materiais Virtuais e Inteligência Artificial

Projectos

Projeto de Investigação Exploratória: Manuel Melle (IF Manuel Melle)

CICECO - Aveiro Institute of Materials (UIDB/50011/2020)

CICECO - Aveiro Institute of Materials (UIDP/50011/2020)

Nano-argilas para remoção/captura de fosfatos (P) e sua reutilização como fertilizante (NATURAL)

agradecimentos

V.M. and C.B. contributed equally to this work. C.B. and V.M. acknowledge the support from the University of Vienna via the Vienna Doctoral School. V.M. and T.P. acknowledge the contribution from the Austrian Science Fund (FWF) via the research project P30431-N36. P.A. acknowledges the contribution of the COST Action CA15107 MultiComp and the COST Action EsSENce CA119, supported by the European Cooperation in Science and Technology(COST). J.L. and M.M.F. acknowledge support through the project IF/00894/2015, the advanced computing project CPCA/A2/2524/2020 granting access to the Navigator cluster at LCA-UC and within the scope of the project CICECO-Aveiro Institute of Materials, UIDB/50011/2020 & UIDP/50011/2020 funded by national funds through the Portuguese Foundation for Science and Technology I.P./MCTES. L.S. acknowledges support by the National Natural Science Foundation of China (No. 51902353), Guangdong Basic and Applied Basic Research Foundation (No. 2019A1515011227), and State Key Laboratory of Optoelectronic Materials and Technologies (No.OEMT-2021-PZ-02). K.C. thanks the support from the Shanghai Post-Qi-Ming-Xing Plan for Young Scientists, China (Grant No. 21QA1406300). K.Y. acknowledges the support from JST CREST Grant Number JPMJCR17I5.