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

详细信息    查看全文

• 作者：Amgad R. Rezk ; Benjamin Carey ; Adam F. Chrimes ; Desmond W. M. Lau ; Brant C. Gibson ; Changxi Zheng ; Michael S. Fuhrer ; Leslie Y. Yeo ; Kourosh Kalantar-zadeh
• 刊名：Nano Letters
• 出版年：2016
• 出版时间：February 10, 2016
• 年：2016
• 卷：16
• 期：2
• 页码：849-855
• 全文大小：404K
• ISSN：1530-6992

文摘

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.