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Empty‐State Band Mapping Using Momentum‐Resolved Secondary Electron Emission
Author(s) -
Wan Gary,
Croot Alex,
Fox Neil A.,
Cattelan Mattia
Publication year - 2021
Publication title -
advanced functional materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 6.069
H-Index - 322
eISSN - 1616-3028
pISSN - 1616-301X
DOI - 10.1002/adfm.202007319
Subject(s) - materials science , secondary emission , diamond , photoelectric effect , electronic band structure , band gap , electron , quasi fermi level , atomic physics , inverse photoemission spectroscopy , electronic structure , effective mass (spring–mass system) , angle resolved photoemission spectroscopy , condensed matter physics , direct and indirect band gaps , optoelectronics , physics , quantum mechanics , composite material
Material band structures of occupied electronic states are obtainable using conventional angle‐resolved photoemission experiments, leaving the unoccupied states far less explored. Here, an alternative approach is built on and expanded to investigate thermalized photoelectrons emitted from crystal surfaces. A model for electron emission is constructed and reveals the material unoccupied state band structure. Potentially applicable to any material and independent from the secondary electron generation mechanism, it is demonstrated on diamond and copper using different light sources. Moreover, the diamond indirect band gap is directly observed and the transverse effective mass at the conduction band minimum can be experimentally obtained, m t = (0.21 ± 0.015) m e . This offers a convenient path for angle‐resolved photoemission data interpretation and empty‐state information extraction.