Premium
Giant Phononic Anisotropy and Unusual Anharmonicity of Phosphorene: Interlayer Coupling and Strain Engineering
Author(s) -
Cai Yongqing,
Ke Qingqing,
Zhang Gang,
Feng Yuan Ping,
Shenoy Vivek B.,
Zhang YongWei
Publication year - 2015
Publication title -
advanced functional materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 6.069
H-Index - 322
eISSN - 1616-3028
pISSN - 1616-301X
DOI - 10.1002/adfm.201404294
Subject(s) - phosphorene , materials science , zigzag , phonon , anharmonicity , anisotropy , brillouin zone , condensed matter physics , strain engineering , monolayer , coupling (piping) , nanoelectronics , graphene , semiconductor , band gap , optoelectronics , nanotechnology , physics , optics , silicon , composite material , geometry , mathematics
Phosphorene, an emerging elemental 2D direct band gap semiconductor with fascinating structural and electronic properties distinctively different from other 2D materials such as graphene and MoS 2 , is promising for novel nanoelectronic and optoelectronic applications. Phonons, as one of the most important collective excitations, are at the heart of the device performance, as their interactions with electrons and photons govern the carrier mobility and light‐emitting efficiency of the material. Here, through a detailed first‐principles study, it is demonstrated that monolayer phosphorene exhibits a giant phononic anisotropy, and remarkably, this anisotropy is squarely opposite to its electronic counterpart and can be tuned effectively by strain engineering. By sampling the whole Brillouin zone for the monolayer phosphorene, several “hidden” directions are found, along which small‐momentum phonons are “frozen” with strain and possess the smallest degree of anharmonicity. Unexpectedly, these “hidden” directions are intrinsically different from the usually‐studied armchair and zigzag directions. Light is also shed on the anisotropy of interlayer coupling of few‐layer phosphorene by examining the rigid‐layer vibrations. These highly anisotropic and strain‐tunable characteristics of phosphorene offer new possibilities for its applications in thermal management, thermoelectronics, nanoelectronics, and phononics.