Photoluminescence enhancement of monolayer MoS2 using plasmonic gallium nanoparticles

2D monolayer molybdenum disulphide (MoS2) has been the focus of intense research due to its direct bandgap compared with the indirect bandgap of its bulk counterpart; however its photoluminescence (PL) intensity is limited due to its low absorption efficiency. Herein, we use gallium hemispherical nanoparticles (Ga NPs) deposited by thermal evaporation on top of chemical vapour deposited MoS2 monolayers in order to enhance its luminescence. The influence of the NP radius and the laser wavelength is reported in PL and Raman experiments. In addition, the physics behind the PL enhancement factor is investigated. The results indicate that the prominent enhancement is caused by the localized surface plasmon resonance of the Ga NPs induced by a charge transfer phenomenon. This work sheds light on the use of alternative metals, besides silver and gold, for the improvement of MoS2 luminescence. © 2019 The Royal Society of Chemistry

Photoluminescence enhancement of monolayer MoS2 using plasmonic gallium nanoparticles

[EN] 2D monolayer molybdenum disulphide (MoS) has been the focus of intense research due to its direct bandgap compared with the indirect bandgap of its bulk counterpart; however its photoluminescence (PL) intensity is limited due to its low absorption efficiency. Herein, we use gallium hemispherical nanoparticles (Ga NPs) deposited by thermal evaporation on top of chemical vapour deposited MoS monolayers in order to enhance its luminescence. The influence of the NP radius and the laser wavelength is reported in PL and Raman experiments. In addition, the physics behind the PL enhancement factor is investigated. The results indicate that the prominent enhancement is caused by the localized surface plasmon resonance of the Ga NPs induced by a charge transfer phenomenon. This work sheds light on the use of alternative metals, besides silver and gold, for the improvement of MoS luminescence.The research is supported by the MINECO (CTQ2014-53334-C2-2-R, MAT2015-65356-C3-1-R and CTQ2017-84309-C2-2-R) and Comunidad de Madrid (NANOAVANSENS ref. S2013/MIT-3029) and UAM-Santander (2017/EEUU/14) projects. ARC acknowledges the Ramón y Cajal program (under contract number RYC-2015-18047). FN acknowledges support from the Marie Sklodowska-Curie grant agreement No. 641899 from the European Union's Horizon 2020 research and innovation programme

Photoluminescence enhancement of monolayer MoS2 using plasmonic gallium nanoparticles

2D monolayer molybdenum disulphide (MoS2) has been the focus of intense research due to its direct bandgap compared with the indirect bandgap of its bulk counterpart; however its photoluminescence (PL) intensity is limited due to its low absorption efficiency. Herein, we use gallium hemispherical nanoparticles (Ga NPs) deposited by thermal evaporation on top of chemical vapour deposited MoS2 monolayers in order to enhance its luminescence. The influence of the NP radius and the laser wavelength is reported in PL and Raman experiments. In addition, the physics behind the PL enhancement factor is investigated. The results indicate that the prominent enhancement is caused by the localized surface plasmon resonance of the Ga NPs induced by a charge transfer phenomenon. This work sheds light on the use of alternative metals, besides silver and gold, for the improvement of MoS2 luminescenceThe research is supported by the MINECO (CTQ2014-53334-C2-2-R, MAT2015-65356-C3-1-R and CTQ2017-84309-C2-2-R) and Comunidad de Madrid (NANOAVANSENS) ref. S2013/MIT-3029) and UAM-Santander (2017/EEUU/14) projects. ARC acknowledges the Ramón y Cajal program (under contract number RYC-2015-18047). FN acknowledges support from the Marie Sklodowska-Curie grant agreement No.641899 from the European Union's Horizon 2020 research and innovation programm