TY - JOUR
T1 - Element- and Site-Specific Many-Body Interactions in Few-Layer MoS2 During X-Ray Absorption Processes
AU - Kamada, Gen
AU - Venugopal, Gunasekaran
AU - Kotsugi, Masato
AU - Ohkochi, Takuo
AU - Suemitsu, Maki
AU - Fukidome, Hirokazu
N1 - Funding Information:
G.K. and G.V. contributed equally to this work. The authors appreciate the support of the staffs at SPring-8 (Contract number: 2015A1278, 2015A1865, and 2015B1199). This work was partially supported by KAKENHI (15H03560 and 16H00953).
Publisher Copyright:
© 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
PY - 2019/1/23
Y1 - 2019/1/23
N2 - Few-layer MoS2 is a promising 2D material for nano-electronic device applications. However, the performance of these devices is often deteriorated. One of the reasons is that the electronic properties are influential to the many-body effects such as excitonic effects and Anderson orthogonality catastrophe (AOC) which could renormalize the band-dispersion and density-of-states(DOS). Hence, the authors investigate the effect of many-body interactions on MoS2 device performance by using X-ray absorption spectro-microscopy (µ-XAS) on a few-layer MoS2 transistor in operation, through the application of gate-bias or contact with a metal. The results show a significant peak shift in µ-XAS spectra while varying the gate-bias. The applied negative gate-bias induces more holes which attracts excited electrons resulting strong many-body interactions followed by Fermi level shift. This effect is discussed with the aid of XAS-Auger electron phenomena. However, the AOC contribution in XAS peak-intensity is ignored since the bands around the energy-gap in MoS2 are relatively flat and the DOS is empty above Fermi level (unlike graphene). The authors observe a redshift in photon energy near the MoS2/metal-electrode interface due to charge transfer ensuring carrier-doping induced through metal-contact. These observations provide significant insight into element- and site-specific many-body interactions in MoS2 tunable by gate-bias or contact with a metal.
AB - Few-layer MoS2 is a promising 2D material for nano-electronic device applications. However, the performance of these devices is often deteriorated. One of the reasons is that the electronic properties are influential to the many-body effects such as excitonic effects and Anderson orthogonality catastrophe (AOC) which could renormalize the band-dispersion and density-of-states(DOS). Hence, the authors investigate the effect of many-body interactions on MoS2 device performance by using X-ray absorption spectro-microscopy (µ-XAS) on a few-layer MoS2 transistor in operation, through the application of gate-bias or contact with a metal. The results show a significant peak shift in µ-XAS spectra while varying the gate-bias. The applied negative gate-bias induces more holes which attracts excited electrons resulting strong many-body interactions followed by Fermi level shift. This effect is discussed with the aid of XAS-Auger electron phenomena. However, the AOC contribution in XAS peak-intensity is ignored since the bands around the energy-gap in MoS2 are relatively flat and the DOS is empty above Fermi level (unlike graphene). The authors observe a redshift in photon energy near the MoS2/metal-electrode interface due to charge transfer ensuring carrier-doping induced through metal-contact. These observations provide significant insight into element- and site-specific many-body interactions in MoS2 tunable by gate-bias or contact with a metal.
KW - MoS
KW - X-ray absorption spectromicroscopy
KW - element- and site-specific
KW - many-body interactions
UR - http://www.scopus.com/inward/record.url?scp=85058683579&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85058683579&partnerID=8YFLogxK
U2 - 10.1002/pssa.201800539
DO - 10.1002/pssa.201800539
M3 - Article
AN - SCOPUS:85058683579
VL - 216
JO - Physica Status Solidi (A) Applications and Materials Science
JF - Physica Status Solidi (A) Applications and Materials Science
SN - 1862-6300
IS - 2
M1 - 1800539
ER -