Naslov
Spatial distribution of bound excitons in CVD grown mono- and bilayers MoS2 in low-temperature regime

Autori
Senkić, Ana ; Supina, Antonio ; Vujičić, Nataša

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, neobjavljeni rad, znanstveni

Skup
Graphene 2021

Mjesto i datum
Grenoble, Francuska, 26.-29.10.2021

Vrsta sudjelovanja
Poster

Vrsta recenzije
Nije recenziran

Ključne riječi
Monolayer molybdenum disulfide, intrinsic defects, low-temperature photoluminescence

Sažetak
In this work we investigated how sulphur concentration affects the electronic structure of CVD grown MoS2 samples. Understanding defect influence on optical and transport properties of MoS2 samples is of great importance since this material has promising application in optics and optoelectronics [1]. In order to have a systematic approach, we investigated samples grown under different synthesis parameters, namely, growth temperature TG, sulphur temperature TS and argon flow Φ. Using two complementary techniques, micro- photoluminescence (PL) optical mapping and AFM, at certain synthesis parameters, discrepancies between edges and central parts of MoS2 flakes were observed, as shown in Figure 1. Possible explanation for this behaviour is the increased defect concentration, primarily sulphur vacancies [2], [3], [4] at the sample edges. Line profile of the KPFM measurement implies that the edges of the MoS2 flake are negatively charged with respect to the middle part, which suggests the change in the electronic structure. We investigated sulphur vacancies and their influence on optical spectra in the low-temperature limit using PL micro- spectroscopy. Low-temperature optical spectra reveal additional feature corresponding to the bound excitons. Spectral contribution of such bound excitons in overall optical response of the crystal provides us with quantitative information on defect states, as well as their spatial distribution.

Izvorni jezik
Engleski

Znanstvena područja
Fizika

Napomena
Sažetak dostupan na web-stranici:
https://www.grapheneconf.com/2021/posters.php

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