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SUMMARY:Air-Stable Electron Depletion of Bi2Se3 Using Molybdenum Trioxide 
 into the Topological Regime
DTSTART;VALUE=DATE-TIME:20141120T063000Z
DTEND;VALUE=DATE-TIME:20141120T080000Z
DTSTAMP;VALUE=DATE-TIME:20260809T075109Z
UID:indico-contribution-701@events01.synchrotron.org.au
DESCRIPTION:Speakers: Mark Edmonds (Monash University)\nTopological insula
 tors\, such as Bi2Se3\, are a new class of material that possess topologic
 ally protected Dirac surface states that hold great promise for next gener
 ation nano-electronic devices [1]. However\, major challenges exist in rea
 lizing Bi2Se3 devices that operate in the topological regime in air. The f
 irst is that as-prepared Bi2Se3 is invariably n-type doped due to selenium
  vacancies [1]\, where the Fermi level resides in the bulk conduction band
 \, not within the Dirac surface states necessary to realize these electron
 ic devices. The second is that Bi2Se3 when exposed to atmosphere becomes f
 urther n-type doped and degrades over time [2].\n\nUtilizing high-resoluti
 on photoelectron spectroscopy on in-situ cleaved Bi2Se3 single crystals we
  demonstrate that the strong electron acceptor molybdenum trioxide (MoO3) 
 is capable of depleting ~1013 cm-2 electrons from Bi2Se3 to place the Ferm
 i level well within the topological regime. We implement a doping model ba
 sed on Fermi-Dirac statistics to accurately describe the doping behaviour 
 as a function of MoO3 coverage. Furthermore\, in-situ transport measuremen
 ts on MBE grown Bi2Se3 films are used to demonstrate that a 100 nm film of
  MoO3 is also capable of protecting Bi2Se3 from degradation upon exposure 
 to atmosphere and further n-type doping [3].\n\n\n\nReferences:\n[1] Y. Xi
 a\, et al.\, Nature Physics 5\, 398 (2009)\n[2] D. Kong\, et al.\, ACS Nan
 o 5\, 4698 (2011).\n[3] M. T. Edmonds\, et al.\, ACS Nano 8\, 6400 (2014).
 \n\nhttps://events01.synchrotron.org.au/event/3/contributions/701/
LOCATION: NCSS Exhibition Area
URL:https://events01.synchrotron.org.au/event/3/contributions/701/
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