Surface & Interface Modeling
for Emerging Nanomaterials and Devices

Interlayer electronic hybridization leads to exceptional thickness-dependent vibrational properties in few-layer black phosphorus

Zhixin Hu,1,2 Xianghua Kong,1,2, Jingsi Qiao,1,2, Bruce Normand1,2 and Wei Ji1,2,

1Department of Physics, Renmin University of China, Beijing 100872, China

2Beijing Key Laboratory of Optoelectronic Functional Materials & Micro-Nano Devices, Renmin University of China, Beijing 100872, China

DOI:10.1039/C5NR06293D     Publication Date: 


Few-layer black phosphorus (FLBP) is a material with high potential for nano- and optoelectronics applications. We perform a theoretical investigation of its vibrational properties by discussing six Raman-observable phonons, including three optical, one breathing and two shear modes. With increasing sample thickness, we find anomalous redshifts of the frequencies for each optical mode but a blueshift for the armchair shear mode. Our calculations also show splitting of the phonon branches, due to anomalous surface effects, and strong phonon-phonon coupling. By computing uniaxial stress effects, inter-atomic force constants and electron densities, we provide a compelling demonstration that these properties are the consequence of strong and highly directional interlayer interactions arising from electronic hybridization of the lone electron-pairs of FLBP. This exceptional interlayer coupling mechanism governs the stacking stability of BP layers and thus opens a new avenue beyond van der Waals epitaxy for understanding the design of two-dimensional heterostructures. 


View: Nanoscale  8, 2740 (2016)     arXiv:1503.06735    

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