Main content area

Two-Dimensional PC₆ with Direct Band Gap and Anisotropic Carrier Mobility

Yu, Tong, Zhao, Ziyuan, Sun, Yuanhui, Bergara, Aitor, Lin, Jianyan, Zhang, Shoutao, Xu, Haiyang, Zhang, Lijun, Yang, Guochun, Liu, Yichun
Journal of the American Chemical Society 2019 v.141 no.4 pp. 1599-1605
absorbance, anisotropy, functional properties, graphene, photovoltaic cells, semiconductors
Graphene and phosphorene are two major types of atomically thin two-dimensional materials under extensive investigation. However, the zero band gap of graphene and the instability of phosphorene greatly restrict their applications. Here, we make first-principle unbiased structure search calculations to identify a new buckled graphene-like PC₆ monolayer with a number of desirable functional properties. The PC₆ monolayer is a direct-gap semiconductor with a band gap of 0.84 eV, and it has an extremely high intrinsic conductivity with anisotropic character (i.e., its electron mobility is 2.94 × 10⁵ cm² V–¹ s–¹ along the armchair direction, whereas the hole mobility reaches 1.64 × 10⁵ cm² V–¹ s–¹ along the zigzag direction), which is comparable to that of graphene. On the other hand, PC₆ shows a high absorption coefficient (10⁵ cm–¹) in a broad band, from 300 to 2000 nm. Additionally, its direct band gap character can remain within a biaxial strain of 5%. All these appealing properties make the predicted PC₆ monolayer a promising candidate for applications in electronic and photovoltaic devices.