C3 N-A 2D Crystalline, Hole-Free, Tunable-Narrow-Bandgap Semiconductor with Ferromagnetic Properties

Siwei Yang; Wei Li; Caichao Ye; Gang Wang; He Tian; Chong Zhu; Peng He; Guqiao Ding; Xiaoming Xie; Yang Liu; Yeshayahu Lifshitz; Shuit-Tong Lee; Zhenhui Kang; Mianheng Jiang

doi:10.1002/adma.201605625

C₃ N-A 2D Crystalline, Hole-Free, Tunable-Narrow-Bandgap Semiconductor with Ferromagnetic Properties

Adv Mater. 2017 Apr;29(16). doi: 10.1002/adma.201605625. Epub 2017 Feb 27.

Authors

Siwei Yang¹, Wei Li^{1

2}, Caichao Ye¹, Gang Wang¹, He Tian³, Chong Zhu¹, Peng He¹, Guqiao Ding¹, Xiaoming Xie^{1

4}, Yang Liu⁵, Yeshayahu Lifshitz^{5

6}, Shuit-Tong Lee⁵, Zhenhui Kang⁵, Mianheng Jiang^{1

4}

Affiliations

¹ State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, 865 Changning Road, Shanghai, 200050, P. R. China.
² Department of Physics and State Key Laboratory of Surface Physics, Fudan University, Shanghai, 200433, China.
³ Center of Electron Microscopy and State Key Laboratory of Silicon Materials, School of Materials Science and Engineering, Zhejiang University, Hangzhou, 310027, P. R. China.
⁴ School of Physical Science and Technology, Shanghai Tech University, Shanghai, 200031, P. R. China.
⁵ Jiangsu Key Laboratory for Carbon-Based Functional Materials and Devices, Institute of Functional Nano and Soft Materials (FUNSOM), Soochow University, Suzhou, 215123, P. R. China.
⁶ Department of Materials Science and Engineering, Technion, Israel Institute of Technology, Haifa, 3200003, Israel.

PMID: 28240434
DOI: 10.1002/adma.201605625

Abstract

Graphene has initiated intensive research efforts on 2D crystalline materials due to its extraordinary set of properties and the resulting host of possible applications. Here the authors report on the controllable large-scale synthesis of C₃ N, a 2D crystalline, hole-free extension of graphene, its structural characterization, and some of its unique properties. C₃ N is fabricated by polymerization of 2,3-diaminophenazine. It consists of a 2D honeycomb lattice with a homogeneous distribution of nitrogen atoms, where both N and C atoms show a D_6h -symmetry. C₃ N is a semiconductor with an indirect bandgap of 0.39 eV that can be tuned to cover the entire visible range by fabrication of quantum dots with different diameters. Back-gated field-effect transistors made of single-layer C₃ N display an on-off current ratio reaching 5.5 × 10¹⁰ . Surprisingly, C₃ N exhibits a ferromagnetic order at low temperatures (<96 K) when doped with hydrogen. This new member of the graphene family opens the door for both fundamental basic research and possible future applications.

Keywords: 2D materials; carbon; ferromagnetic properties; semiconductors.