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.Compr...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 MoS_(2)layers remain unclear.Herein,we report ARR spectroscopic features of A,B,interlayer excitons in monolayer(ML)and bilayer(BL)MoS_(2)on three kinds of photonic substrates,involving distinct exciton–photon interactions.In a BL MoS_(2)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 angleinsensitive energy dispersion.When ML and BL MoS_(2)lie on a SiO_(2)-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 MoS_(2)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,interlayer excitons in ML and BL MoS_(2),gaining insights into the interpretation of light–matter interactions in 2D semiconductors and the design of their devices for practical photonic applications.展开更多
基金the National Natural Science Foundation of China(No.61904151)the Joint Research Funds of the Department of Science&Technology of Shaanxi Province and Northwestern Polytechnical University(No.2020GXLH-Z-020)+1 种基金the Fundamental Research Funds for the Central Universities of China,the National Key R&D Program of China(No.2021YFA1200800)the Start-up Funds of Wuhan University.
文摘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 MoS_(2)layers remain unclear.Herein,we report ARR spectroscopic features of A,B,interlayer excitons in monolayer(ML)and bilayer(BL)MoS_(2)on three kinds of photonic substrates,involving distinct exciton–photon interactions.In a BL MoS_(2)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 angleinsensitive energy dispersion.When ML and BL MoS_(2)lie on a SiO_(2)-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 MoS_(2)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,interlayer excitons in ML and BL MoS_(2),gaining insights into the interpretation of light–matter interactions in 2D semiconductors and the design of their devices for practical photonic applications.
