Energy transfer in a type-I van der Waals heterostructure of WSe2/PtSe2. (1st July 2022)

• Record Type: Journal Article
• Authors: Wang, Pengzhi; Wang, Yongsheng; Bian, Ang; Hao, Shengcai; Miao, Qing; Zhang, Xiaoxian; He, Jiaqi; He, Dawei; Zhao, Hui
• Is Part Of: 2D materials. Volume 9:Number 3(2022)
• Publication Date: 2022-07-01
• Subjects: PtSe2 -- van der Waals heterostructure -- energy transfer -- transient absorption spectroscopy; Graphene -- Periodicals; Materials science -- Periodicals; Nanostructured materials -- Periodicals; 620.115
• DOI: 10.1088/2053-1583/ac75f2
• Languages: English
• ISSNs: 2053-1583

Abstract

Abstract: Energy transfer of a van der Waals heterostructure formed by monolayers of WSe2 and PtSe2 is studied by steady-state photoluminescence (PL) and time-resolved transient absorption spectroscopy. The heterostructure sample is fabricated by transferring a mechanically exfoliated WSe2 monolayer onto a PtSe2 monolayer film obtained by chemical vapor deposition. The sample is thermally annealed to improve the interface quality. PL of the heterostructure is quenched by four times compared to the individual WSe2 monolayer, indicating excitation transfer from WSe2 to PtSe2 . Femtosecond transient absorption measurements with two configurations show that both the electrons and the holes can transfer from WSe2 to PtSe2 on a sub-picosecond time scale, while neither can transfer from PtSe2 to WSe2 . These results indicate that WSe2 and PtSe2 monolayers form a type-I band alignment with both the conduction band minimum and the valence band maximum in the PtSe2 layer.