Todas as Publicações do INCT-MI

@article{CANCADO2024118801,

title = {Science and Metrology of defects in graphene using Raman Spectroscopy},

author = {Luiz G. Cançado and Victor P. Monken and João Luiz E. Campos and Joyce C. C. Santos and Claudia Backes and Hélio Chacham and Bernardo R. A. Neves and Ado Jorio},

url = {https://www.sciencedirect.com/science/article/pii/S0008622324000186},

doi = {https://doi.org/10.1016/j.carbon.2024.118801},

issn = {0008-6223},

year  = {2024},

date = {2024-01-11},

urldate = {2024-01-01},

journal = {Carbon},

pages = {118801},

abstract = {This article offers a historical account of the evolution of defect metrology in graphene through Raman spectroscopy over the past five decades. The application of Raman scattering to the investigation of disorder levels in graphite materials dates back to the 1970s, and substantial advancements have occurred in this field, especially following the isolation of graphene in 2006. The article starts presenting the physics related to structural defects disrupting the translational symmetry in crystalline solids, introducing a relaxation of selection rules in Raman spectroscopy that manifests as peaks induced by disorder, then it delves into significant milestones and provides a practical summary of the principal existing protocols. Furthermore, we explore the contribution of tip-enhanced Raman spectroscopy to gaining deeper insights into fundamental aspects of defects in graphene materials, owing to its capacity for spectroscopic measurements with high spatial resolution. In conclusion, we outline prospects for the further utilization of this innovative technique in enhancing both the science and metrology of defects in graphene and its applications in other two-dimensional systems.},

keywords = {Defects, Grapehene, Line defects, Liquid-phase exfoliation, Number of layers, Point defects, Raman spectroscopy, Tip-enhanced raman spectroscopy},

pubstate = {published},

tppubtype = {article}

}

@article{ESPINOSAGARCIA2023172264,

title = {Intrinsic defects in sulvanite compounds: the case of transparent Cu3TaS4 and absorbing Cu3VSe4},

author = {W. F. Espinosa-García and Gustavo M. Dalpian and J. M. Osorio-Guillén},

url = {https://www.sciencedirect.com/science/article/pii/S0925838823035673},

doi = {https://doi.org/10.1016/j.jallcom.2023.172264},

issn = {0925-8388},

year  = {2023},

date = {2023-09-25},

urldate = {2023-01-01},

journal = {Journal of Alloys and Compounds},

pages = {172264},

abstract = {Sulvanites are semiconducting compounds with the chemical formula Cu3TMX4 where TM = V, Nb, Ta; X = S, Se, Te. Semiconductor electronic and optical properties are highly influenced by intrinsic defects such as vacancies, antisites, and atoms residing in interstitial positions inside the crystal structure. Even though intrinsic defects are extremely important, very little is known about defects in sulvanites. Here we report the properties of all intrinsic defects in two representative sulvanite compounds (Cu3TaS4 and Cu3VSe4) by using computational quantum mechanical methods. Our results indicate that Cu vacancies are the most frequent defects in these compounds, also responsible for limiting the possibility of their n-type doping and setting the pinning of the Fermi energy to positions close to the valence band. These results explain why as-grown sulvanites are usually p-type and open a path for understanding the search for ways to design and tune the properties of these compounds.},

keywords = {Defects, First-principles calculations, P-type materials, Semiconductors, Sulvanite},

pubstate = {published},

tppubtype = {article}

}