Síntese e caracterização de heteroestruturas bidimensionais de TMDs

Abstract

In this work, were study the general characteristics and growth methods of transition metal dichalcogenides (TMD) and their heterostructures (HS). The aimed was the synthesis of molybdenum disulfide (MoS2) to enable the growth of a MoSe2-MoS2 heterojunction by the chemical vapor deposition (CVD) method, that is, to grow an HS without the use of transfer between substrates, something rarely found in the literature. With these samples, it was possible to analyze the optoelectronic behavior of this nanomaterial, through Raman and photoluminescence spectroscopy. Optical and electron microscopy were also used. It was observed that in the synthesized heterostructures, each layer of the grown TMDs underwent changes in their crystal lattices to obtain a more stable configuration. This increases the coupling effect between the layers, enabling observations of trions, a bound state formed by the attraction of two electrons (holes) and a hole (electron), as well as changes in the vibrations of the materials' lattice.