Giant Narrow-Band Optical Absorption and Distinctive Excitonic Structures of Monolayer C3 N and C3 B

Tang，Zhao1; Cruz，Greis J.1; Wu，Yabei2; Xia，Weiyi3; Jia，Fanhao1,4; Zhang，Wenqing2; Zhang，Peihong1

2022-03-01

10.1103/PhysRevApplied.17.034068

Physical Review Applied   影响因子和分区

2331-7019

2331-7019

Low-dimensional materials provide a unique platform for exploring exotic properties that are otherwise unachievable in bulk solids. C3N and C3B are two graphene-derived two-dimensional (2D) ordered alloys that have attracted increasing research attention. These materials are best known for their remarkable stability and moderate band gaps, and thus, are suitable for a range of applications. Perhaps the most interesting feature of the electronic structures of C3N and C3B is the existence of nearly parallel valence and conduction bands across a large region of the Brillouin zone. In this work, using many-body perturbation theory within the GW and Bethe-Salpeter-equation approach, we predict that the primarily pz-orbital-derived nearly parallel valence and conduction bands in monolayer C3N and C3B give rise to a giant narrow-band absorption peak in their optical absorption spectra. More surprisingly, two degenerate excitonic states contribute to over 90% and 80% of the dipole absorption below 5 eV for C3N and C3B, respectively. Detailed examinations of the exciton-binding energies unveil a unique shell-like distribution of the excitonic states, with each shell (series) converging to a different excitation edge. Such distinctive absorption properties are not observed in any other 2D materials. We further investigate the internal structure of the excitonic states using a multifaceted approach and reveal several important characteristics of the excitonic states in these 2D materials.

SCI ; EI

英语

其他

National Science Foun-dation["DMR-1506669","DMREF-1626967"] ; National Natural Science Foundation of China[12104207,11929401]

Physics

Physics, Applied

WOS:000782849100001

AMER PHYSICAL SOC

20221511936504

Binding energy ; Chemical industry ; Conduction bands ; Energy gap ; Light absorption ; Monolayers ; Perturbation techniques

Light/Optics:741.1 ; Physical Chemistry:801.4 ; Chemical Engineering, General:805 ; Mathematics:921 ; High Energy Physics:932.1

2-s2.0-85127463852

Scopus

1.Department of Physics,University at Buffalo,State University of New York,Buffalo,14260,United States
2.Department of Materials Science and Engineering,Shenzhen Inst. for Quant. Sci. and Engineering,and Academy for Advanced Interdisciplinary Studies,Southern University of Science and Technology,Guangdong,Shenzhen,518055,China
3.Department of Physics and Astronomy,Iowa State University,Ames,50011,United States
4.Sch. of Mat. Science and Engineering and International Centre of Quantum and Molecular Structures,Shanghai University,Shanghai,200444,China

Tang，Zhao,Cruz，Greis J.,Wu，Yabei,et al. Giant Narrow-Band Optical Absorption and Distinctive Excitonic Structures of Monolayer C3 N and C3 B[J]. Physical Review Applied,2022,17(3).

Tang，Zhao.,Cruz，Greis J..,Wu，Yabei.,Xia，Weiyi.,Jia，Fanhao.,...&Zhang，Peihong.(2022).Giant Narrow-Band Optical Absorption and Distinctive Excitonic Structures of Monolayer C3 N and C3 B.Physical Review Applied,17(3).

Tang，Zhao,et al."Giant Narrow-Band Optical Absorption and Distinctive Excitonic Structures of Monolayer C3 N and C3 B".Physical Review Applied 17.3(2022).