Advanced search
Start date
Betweenand

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

Grant number: 18/04926-9
Support type:Scholarships abroad - Research Internship - Post-doctor
Effective date (Start): August 01, 2018
Effective date (End): July 31, 2019
Field of knowledge:Physical Sciences and Mathematics - Physics - Condensed Matter Physics
Principal Investigator:Christiano José Santiago de Matos
Grantee:Henrique Bücker Ribeiro
Supervisor abroad: Tony F. Heinz
Home Institution: Centro de Pesquisas Avançadas em Grafeno, Nanomateriais e Nanotecnologia (MackGrafe). Universidade Presbiteriana Mackenzie (UPM). Instituto Presbiteriano Mackenzie. São Paulo , SP, Brazil
Local de pesquisa : Stanford University, United States  
Associated to the scholarship:17/20100-0 - Spectroscopy of excitonic and many body effects in two-dimensional materials, BP.PD

Abstract

Excitons in two-dimensional 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 binding 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 complex quasi-particles, such as trions and biexcitons, 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. In order to attain devices (such as light emitters, detectors, photovoltaic cells, and nonlinear optical devices) based on such effects, the study of the fundamental physics of these quasi-particles in 2D semiconductors is fundamental. However, investigations in this area are 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), presenting interesting additional properties such as anisotropy, which require more research. The main goal of the present proposal is the spectroscopic study of these 2D semiconductors. The effects of the dielectric environment on the binding energy of the quasi-particles will be investigated by means of photoluminescence, photoluminescence excitation and Raman spectroscopy. The lifetime of the quasi-particles will be investigated by means of time-resolved spectroscopic techniques.

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.

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