Emerging 2D Materials with Nonparabolic Bands for Ultrafast Photonics
Guanyu Liu,
Zhengwei Cui,
Fangteng Zhang,
Youjun Zeng,
Weicheng Chen,
Yuxian Liu,
Zhaogang Nie,
Qiaoliang Bao
Affiliations
Guanyu Liu
School of Physics & Photoelectric Engineering Guangdong University of Technology Guangzhou 510650 China
Zhengwei Cui
Guangdong-Hong Kong-Macao Joint Laboratory for Intelligent Micro-Nano Optoelectronic Technology School of Physics and Optoelectronic Engineering Foshan University Foshan 528000 China
Fangteng Zhang
School of Physics & Photoelectric Engineering Guangdong University of Technology Guangzhou 510650 China
Youjun Zeng
School of Physics & Photoelectric Engineering Guangdong University of Technology Guangzhou 510650 China
Weicheng Chen
Guangdong-Hong Kong-Macao Joint Laboratory for Intelligent Micro-Nano Optoelectronic Technology School of Physics and Optoelectronic Engineering Foshan University Foshan 528000 China
Yuxian Liu
National Key Laboratory of Science and Technology on Micro/Nano Fabrication Institute of Microelectronics School of Electronics Engineering and Computer Science Peking University Beijing 100871 P. R. China
Zhaogang Nie
School of Physics & Photoelectric Engineering Guangdong University of Technology Guangzhou 510650 China
Qiaoliang Bao
Institute of Energy Materials Science (IEMS) University of Shanghai for Science and Technology Shanghai 200093 China
In recent years, 2D materials have been widely used in optical and photonic applications such as mode lockers, optical switches, polarizers, and optical modulators. As is known, many 2D optical materials are parabolic semiconductors. The electronic states determines the material's optical characteristics. The energy band structure with a bandgap dominates the electron dynamics process associated with intrinsic light absorption. Particularly, the Dirac cone and flat band (FB) are special nonparabolic energy band structures in materials. Dirac materials are characterized by a zero bandgap, and FB materials have a completely flat dispersionless band in the Brillouin zone. These materials are used as emergent and promising 2D materials for saturable absorbers (SAs) due to their excellent nonlinear optical response, and they become potential candidates for ultrafast photonics applications. Herein, the focus is on the characteristics of the energy band structure; the carrier dynamics are reviewed, and application in ultrafast photonics are summarized.
