Organic Semiconductors

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Organic Semiconductors
MACQUARIE UNIVERSITY, DEPARTMENT OF
PHYSICS RESEARCH Organic Semiconductors

• Many applications bright, thin, high resolution
  OLED displays, solar cells, transistors, chemical
  sensors
• However, materials and devices are not optimized
  aging problems, no simple inexpensive method to
  pattern organic semiconductor thin-films

• We are trying to understand and engineer organic
  semiconductor interfaces, and to develop new ways
  to pattern OS thin films
• More detailed electronic information is obtained
  using synchrotron techniques
• Density functional (DFT) techniques are used to
  predict OS properties
• Active collaborations with groups in the US and
  Ireland on the growth and synchrotron
  characterisation of organic semiconductors

Dr James Downes james.downes_at_mq.edu.au Ph.
9850-8900
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MACQUARIE UNIVERSITY, DEPARTMENT OF
PHYSICS RESEARCH Rare Earth Nitride Magnetic
Semiconductors

• Recent theoretical work has shown that several of
  the rare-earth nitrides may be spin polarized
  semiconductors (different band gaps for spin
  up/down)
• Magnetic semiconductors are useful for the
  development of spintronic devices electronics
  that use electronic spin to carry and process
  information

• We are
• Growing and characterizing the samples in ultra
  high vacuum at the synchrotron
• Developing new deposition techniques, including
  AlN, YZO capping layers, to protect samples
  from the atmosphere
• Moving towards epitaxial single crystal growth
  for lab-based optical characterization
• Active international collaboration involving New
  Zealand 2 x US researchers

Dr James Downes james.downes_at_mq.edu.au Ph.
9850-8900
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MACQUARIE UNIVERSITY, DEPARTMENT OF
PHYSICS RESEARCH Synchrotron-Based Spectroscopy
of Novel Materials

• Use high-brightness synchrotron soft x-ray
  undulator source
• X-ray absorption and emission spectroscopies
  provide detailed electronic information on novel
  materials that no other local technique can
• Travel to US and Swedish synchrotron sources
• Developing resources at the new Australian
  Synchrotron (Melbourne)

Dr James Downes james.downes_at_mq.edu.au Ph.
9850-8900
Australian Synchrotron
National Synchrotron Light Source, Brookhaven
National Lab. (USA)