Spectroscopic Study of the Excitonic Structure in Monolayer MoS2 under Multivariate Physical and Chemical Stimuli
Viktor Bender, Tobias Bucher, Mohammad Nasimuzzaman Mishuk, and 6 more authors
physica status solidi (a), 2024
Photoluminescence (PL) spectroscopy has proven to provide deep insights into the optoelectronic properties of monolayer MoS2}łeft(}textMoS}right)_2}. Herein, a corresponding study is conducted on the excitonic properties of mechanically exfoliated monolayer MoS2}łeft(}textMoS}right)_2} under multivariate physical and chemical stimuli. Specifically, midgap exciton states that originate from lattice defects are characterized and they are compared to existing models. Through statistical data analyses of substrate-, temperature-, and laser-power-dependent measurements, a PL enhancement is revealed through physisorption of water molecules of the controversially discussed excited-state A biexciton (AXX*}A^łeft(}textXX}right)^}star}). In addition, analyses of monolayer MoS2}łeft(}textMoS}right)_2} on gold substrates show that surface roughness does not account for changes in doping level within the material. Also, a shift in the electron–phonon coupling properties that arises from thin films of water that are physisorbed on top of the samples is reported.