Acoustically-Driven Trion and Exciton Modulation in Piezoelectric Two-Dimensional MoS2

作者:Rezk Amgad R; Carey Benjamin; Chrimes Adam F; Lau Desmond W M; Gibson Brant C; Zheng Changxi; Fuhrer Michael S; Yeo Leslie Y; Kalantar zadeh Kourosh
来源:Nano Letters, 2016, 16(2): 849-855.
DOI:10.1021/acs.nanolett.5b02826

摘要

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.

  • 出版日期2016-2