2D GeP: An Unexploited Low-Symmetry Semiconductor with Strong In-Plane Anisotropy

Liang Li; Weike Wang; Penglai Gong; Xiangde Zhu; Bei Deng; Xingqiang Shi; Guoying Gao; Huiqiao Li; Tianyou Zhai

doi:10.1002/adma.201706771

2D GeP: An Unexploited Low-Symmetry Semiconductor with Strong In-Plane Anisotropy

Adv Mater. 2018 Apr;30(14):e1706771. doi: 10.1002/adma.201706771. Epub 2018 Feb 26.

Authors

Liang Li¹, Weike Wang², Penglai Gong³, Xiangde Zhu⁴, Bei Deng³, Xingqiang Shi³, Guoying Gao⁵, Huiqiao Li¹, Tianyou Zhai^{1

6}

Affiliations

¹ State Key Laboratory of Material Processing and Die and Mould Technology, School of Materials Science and Engineering, Huazhong University of Science and Technology (HUST), Wuhan, 430074, P. R. China.
² Synergetic Innovation Center for Quantum Effects and Application, Key Laboratory of Low-dimensional Quantum Structures and Quantum Control of Ministry of Education, College of Physics and Information Science, Hunan Normal University, Changsha, 410081, P. R. China.
³ Department of Physics, Southern University of Science and Technology, Shenzhen, 518055, P. R. China.
⁴ Anhui Province Key Laboratory of Condensed Matter Physics at Extreme Conditions, High Magnetic Field Laboratory of the Chinese Academy of Science, Hefei, 230031, P. R. China.
⁵ School of Physics, Huazhong University of Science and Technology, Wuhan, 430074, P. R. China.
⁶ Tianjin Key Laboratory of Molecular Optoelectronic Sciences, Department of Chemistry, Tianjin University, and Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin, 300072, P. R. China.

PMID: 29479747
DOI: 10.1002/adma.201706771

Abstract

Germanium phosphide (GeP), a new member of the Group IV-Group V compounds, is introduced into the fast growing 2D family with experimental and theoretical demonstration of strong anisotropic physical properties. The indirect band gap of GeP can be drastically tuned from 1.68 eV for monolayer to 0.51 eV for bulk, with highly anisotropic dispersions of band structures. Thin GeP shows strong anisotropy of phonon vibrations. Moreover, photodetectors based on GeP flakes show highly anisotropic behavior with anisotropic factors of 1.52 and 1.83 for conductance and photoresponsivity, respectively. This work lays the foundation and ignites future research interests in Group IV-Group V compound 2D materials.

Keywords: 2D materials; GeP; in-plane anisotropy; low-symmetry; photodetectors.