Lee Hsun Lecture Series

Topic: Progress in 2D electronic materials beyond graphene

Speaker: Professor David Tománek
　　      Physics and Astronomy Department, Michigan State University, USA

Time: 10:00-12:00,  (Fri.) May 15^th, 2015

Venue: Room 403, Shi Changxu Building, IMR CAS

Abstract:

Graphene monolayers have sparked off unprecedented interest due to their unique electronic structure, but will unlikely replace silicon electronics due to a vanishing fundamental band gap. To still realize the promise of 2D semiconductor electronics, scientists are turning to other layered materials with a nonzero band gap. In this respect, layered structures of group V elements are rapidly attracting interest. Few-layer phosphorus dubbed phosphorene combines high carrier mobility with an unprecedented tunability of the band gap [1-3]. Multiple allotropes of phosphorene, illustrated in Figure 1, may be synthesized by CVD and coexist within a monolayer with virtually no energy penalty to form grain boundaries [3]. Similar to graphene, phosphorene may form fullerenes and nanotubes [4]. There are countless possibilities to tile a phosphorene monolayer with different allotropes, providing the possibility of complex electronic structure patterning [5]. Similar intriguing electronic properties as found in phosphorene are postulated also for arsenene [6], a monolayer of gray arsenic. Computer simulations are a welcome means to gain microscopic insight into the physical properties and possible ways to synthesize these structures, as a guide to experimental efforts.

Reference

[1] David Tománek, 2014 symposium on phosphorene: An emerging 2D semiconductor, Mater. Express 4, 545 (2014).  
[2] Han Liu, Adam T. Neal, Zhen Zhu, Zhe Luo, Xianfan Xu, David Tománek, and Peide D. Ye, ACS Nano 8, 4033 (2014).
[2] Zhen Zhu and David Tománek, Phys. Rev. Lett. 112, 176802 (2014).
[3] Jie Guan, Zhen Zhu, and David Tománek, Phys. Rev. Lett. 113, 046804 (2014).
[4] Jie Guan, Zhen Zhu, and David Tománek, Phys. Rev. Lett. 113, 226801 (2014).
[5] Jie Guan, Zhen Zhu, and David Tománek, ACS Nano 8, 12763 (2014).
[6] Zhen Zhu, Jie Guan, and David Tománek, Phys. Rev. B 91, 161404(R) (2015).