Confined Monolayer Ag As a Large Gap 2D Semiconductor and Its Momentum Resolved Excited States

Woojoo Lee, Yuanxi Wang, Wei Qin, Hyunsue Kim, Mengke Liu, T. Nathan Nunley, Bin Fang, Rinu Maniyara, Chengye Dong, Joshua A. Robinson, Vincent H. Crespi, Xiaoqin Li, Allan H. Macdonald, Chih Kang Shih

Research output: Contribution to journalArticlepeer-review

3 Scopus citations


2D materials have intriguing quantum phenomena that are distinctively different from their bulk counterparts. Recently, epitaxially synthesized wafer-scale 2D metals, composed of elemental atoms, are attracting attention not only for their potential applications but also for exotic quantum effects such as superconductivity. By mapping momentum-resolved electronic states using time-resolved and angle-resolved photoemission spectroscopy (ARPES), we reveal that monolayer Ag confined between bilayer graphene and SiC is a large gap (>1 eV) 2D semiconductor, consistent with ab initio GW calculations. The measured valence band dispersion matches the GW quasiparticle band structure. However, the conduction band dispersion shows an anomalously large effective mass of 2.4 m0. Possible mechanisms for this large enhancement in the "apparent mass" are discussed.

Original languageEnglish (US)
Pages (from-to)7841-7847
Number of pages7
JournalNano letters
Issue number19
StatePublished - Oct 12 2022

All Science Journal Classification (ASJC) codes

  • Bioengineering
  • General Chemistry
  • General Materials Science
  • Condensed Matter Physics
  • Mechanical Engineering


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