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Spectroscopy of excitonic and many body effects in two-dimensional materials

Grant number: 17/20100-0
Support type:Scholarships in Brazil - Post-Doctorate
Effective date (Start): January 01, 2018
Status:Discontinued
Field of knowledge:Physical Sciences and Mathematics - Physics - Condensed Matter Physics
Principal Investigator:Christiano José Santiago de Matos
Grantee:Henrique Bücker Ribeiro
Home Institution: Centro de Pesquisas Avançadas em Grafeno, Nanomateriais e Nanotecnologia (MackGrafe). Universidade Presbiteriana Mackenzie (UPM). Instituto Presbiteriano Mackenzie. São Paulo , SP, Brazil
Associated research grant:15/11779-4 - Plasmonic and nonlinear effects in graphene coupled to optical waveguides, AP.TEM
Associated scholarship(s):18/04926-9 - Spectroscopy of excitonic and many-body effects in two-dimensional materials, BE.EP.PD

Abstract

Excitons in two-dimensional (2D) semiconductors, such as the transition metal dichalcogenides (TMD), prove to be interesting for the study of physics of many body systems. The low dimensionality makes the exciton bond energy high enough to make it stable at room temperature, whereas in three-dimensional crystals the observation of such excitons usually requires low temperatures. Also, more complexes quasi-particles, such as trions and biexciton, become easily observable in 2D materials.In addition, the 2D geometry makes the energy levels easy to manipulate, since the electronic structure depends on the number of layers and the binding energy of the excitons depends on the environment around the crystal. Hence, it is possible to adjust as optical properties of the same, making it ideal for construction of optoelectronic devices, such as light emitters and detectors, photovoltaic cells, nonlinear optical devices, among others. In order to attain such devices, the study of fundamental physics of these quasi-particles in 2D semiconductors is fundamental. However, the focus of investigations in this area is currently focused on TMDs. On the other hand, there are a large number of lamellar semiconductors, such as black phosphorus (BP), germanium sulfide (GeS) and germanium selenide (GeSe), which require more research presenting interesting additional properties such as anisotropy properties excitons and optical bandgap tunable with the thickness. Thus, in this project, we propose the study of many body effects in other two-dimensional semiconductor materials as well as the consequences of their properties. The effects of the dielectric environment on the binding energy of the quasi-particles will be investigated, as well as temperature on the optical transitions, by means of photoluminescence, photoluminescence of excitation and Raman spectroscopy. The lifetime of the quasi-particles will be investigated by means of time-resolved spectroscopic techniques, as a function of the number of crystal layers, substrate, and temperature, in order to understand and control the influence these parameters on the quasi-particles dynamics.

Scientific publications
(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)
MALDONADO, MELISSA; DA SILVA NETO, MANOEL L.; VIANNA, PILAR G.; RIBEIRO, HENRIQUE B.; GORDO, VANESSA O.; CARVALHO, ISABEL C. S.; MENEZES, LEONARDO DE S.; DE ARAUJO, CID B.; DE MATOS, CHRISTIANO J. S.; SEIXAS, LEANDRO; JAWAID, ALI M.; BUSCH, ROBERT; RITTER, ALLYSON J.; VAIA, RICHARD A.; GOMES, ANDERSON S. L. Femtosecond Nonlinear Optical Properties of 2D Metallic NbS2 in the Near Infrared. Journal of Physical Chemistry C, v. 124, n. 28, p. 15425-15433, JUL 16 2020. Web of Science Citations: 0.
RIBEIRO, H. B.; RAMOS, S. L. L. M.; SEIXAS, L.; DE MATOS, C. J. S.; PIMENTA, M. A. Edge phonons in layered orthorhombic GeS and GeSe monochalcogenides. Physical Review B, v. 100, n. 9 SEP 3 2019. Web of Science Citations: 0.
BATISTA, ANDRE JAQUES; VIANNA, PILAR GREGORY; RIBEIRO, HENRIQUE BUCKER; SANTIAGO DE MATOS, CHRISTIANO JOSE; LEONIDAS GOMES, ANDERSON STEVENS. QR code micro-certified gemstones: femtosecond writing and Raman characterization in Diamond, Ruby and Sapphire. SCIENTIFIC REPORTS, v. 9, JUN 20 2019. Web of Science Citations: 1.

Please report errors in scientific publications list by writing to: cdi@fapesp.br.