title: Acoustically-Driven Trion and Exciton Modulation in Piezoelectric Two-Dimensional MoS2.
abstract: By exploiting the very recent discovery of the piezoelectricity in odd-numbered layers of two-dimensional molybdenum disulfide (MoS2), we show the possibility of reversibly tuning the photoluminescence of single and odd-numbered multilayered MoS2 using high frequency sound wave coupling. We observe a strong quenching in the photoluminescence associated with the dissociation and spatial separation of electrons-holes quasi-particles at low applied acoustic powers. At the same applied powers, we note a relative preference for ionization of trions into excitons. This work also constitutes the first visual presentation of the surface displacement in one-layered MoS2 using laser Doppler vibrometry. Such observations are associated with the acoustically generated electric field arising from the piezoelectric nature of MoS2 for odd-numbered layers. At larger applied powers, the thermal effect dominates the behavior of the two-dimensional flakes. Altogether, the work reveals several key fundamentals governing acousto-optic properties of odd-layered MoS2 that can be implemented in future optical and electronic systems.
authors.forename: Amgad R
authors.initials: AR
authors.lastname: Rezk
authors.forename: Benjamin
authors.initials: B
authors.lastname: Carey
authors.forename: Adam F
authors.initials: AF
authors.lastname: Chrimes
authors.forename: Desmond W M
authors.initials: DW
authors.lastname: Lau
authors.forename: Brant C
authors.initials: BC
authors.lastname: Gibson
authors.affiliation: Monash Centre for Atomically Thin Materials, Monash University , Victoria 3800, Australia.
authors.forename: Changxi
authors.initials: C
authors.lastname: Zheng
authors.affiliation: Monash Centre for Atomically Thin Materials, Monash University , Victoria 3800, Australia.
authors.forename: Michael S
authors.initials: MS
authors.lastname: Fuhrer
authors.forename: Leslie Y
authors.initials: LY
authors.lastname: Yeo
authors.forename: Kourosh
authors.initials: K
authors.lastname: Kalantar-Zadeh
keywords: MoS2; Two-dimensional materials; exciton; photoluminesence; piezoelectricity; surface acoustic waves; trion