摘要
Quantum-confined Stark effects(QCSEs),where external or built-in electric fields modify optical transition energies,have garnered significant interest due to their potential for tuning emission energies to couple with quantum dots,metasurfaces,cavities,etc.However,only external electric-field-enabled QCSEs in 2D semiconductors have been reported so far,owing to the challenges posed by small and uncontrollable built-in electric fields,as well as charge modulation effects.We report the first observation of giant built-in electric field-enabled QCSEs in 1L WSe_(2)/1L graphene heterostructure(HS)with an air-gap structure that suppresses graphene screening and bandgap renormalization.Electrical control of QCSEs demonstrates a maximum Stark shift of∼56.97 meV.This significant shift is attributed to enhanced built-in electric fields resulting from the doping-induced increase of chemical potential difference.While increasing optical doping or reducing the interlayer distance,QCSEs weaken due to reduced built-in electric fields.By leveraging efficient exciton dissociations from built-in electric fields,the responsivity(R)and response speed of HS photodetectors increase by 3 orders of magnitude and threefold,respectively,compared with 1L WSe_(2).Our results offer a new avenue for enhancing exciton tunability and exploring device applications of 2D materials in photodetectors,polariton transistors,and quantum light sources.
基金
support from the National Natural Science Foundation of China(NSFC)(Grant Nos.62204117 and 62004086)
the Jiangsu Province Science Foundation for Youths(Grant No.BK20210275)
the Science and Technology Innovation Foundation for Youths(Grant No.NS2022099)
the Postgraduate Research&Practice Innovation Program of Jiangsu Province(Grant No.KYCX220325)
the Research Plan for Short Visit Program,Nanjing University of Aeronautics and Astronautics(NUAA)(Grant No.250101DF08)
the Visiting Scholar Foundation of Key Laboratory of Optoelectronic Technology&Systems(Chongqing University)
Ministry of Education.S.C.Q acknowledges support from the Guangyue Young Scholar Innovation Team of Liaocheng University(Grant No.LUGYTD2023-01)
F.Z.acknowledges support from the Natural Science Foundation of Southwest University of Science and Technology(Grant No.22zx7130).
