@article{Hu2023, 
author = {Hanwei Hu and Xuewen Zhang and Xinyu Zhang and Lishu Wu and Vanessa Li Zhang and Silin He and Guangchao Shi and Ting Yu and Jingzhi Shang},
title = {Probing angle-resolved reflection signatures of intralayer and interlayer excitons in monolayer and bilayer MoS2},
year = {2023},
journal = {Nano Research},
volume = {16},
number = {5},
pages = {7844-7850},
keywords = {MoS2, exciton, exciton–photon coupling, exciton–polariton, angle-resolved reflection},
url = {https://www.sciopen.com/article/10.1007/s12274-022-5292-4},
doi = {10.1007/s12274-022-5292-4},
abstract = {Strongly bound excitons in atomically thin transition metal dichalcogenides offer many opportunities to reveal the underlying physics of basic quasiparticles and many-body effects in the two-dimensional (2D) limit. Comprehensive reflection investigation on band-edge exciton transitions is essential to exploring wealthy light–matter interactions in the emerging 2D semiconductors, whereas angle-resolved reflection (ARR) characteristics of intralayer and interlayer excitons in 2D MoS2 layers remain unclear. Herein, we report ARR spectroscopic features of A, B, and interlayer excitons in monolayer (ML) and bilayer (BL) MoS2 on three kinds of photonic substrates, involving distinct exciton–photon interactions. In a BL MoS2 on a protected silver mirror, the interlayer exciton with one-third amplitude of A exciton appears at 0.05 eV above the A exciton energy, exhibiting an angle-insensitive energy dispersion. When ML and BL MoS2 lie on a SiO2-covered silicon, the broad trapped-photon mode weakly couples with the reflection bands of A and B excitons by the Fano resonance effect, causing the asymmetric lineshapes and the redshifted energies. After transferring MoS2 layers onto a one-dimensional photonic crystal, two high-lying branches of B-exciton polaritons are formed by the interactions between B excitons and Bragg photons, beyond the weak-coupling regime. This work provides ARR spectral benchmarks of A, B, and interlayer excitons in ML and BL MoS2, gaining insights into the interpretation of light–matter interactions in 2D semiconductors and the design of their devices for practical photonic applications.}
}