1. Research Highlights 2001-2010 – N. Pelekanos
PhD 1991: Brown Univ. (USA)
Post-docs: CEA/Grenoble, CNET Lannion, Max-Planck Stuttgart
: CEA/Grenoble
: FORTH & Univ. of Crete
Novel optoelectronic devices - GaAs
Nitrides:
Towards improved optoelectronic devices
Nanowire
solar cells
Piezoelectric quantum dots:
InAs (GaN)
Funding: EC, ΓΓΕΤ, ΥΠΕΠΘ,..., 2,9 million Euros
FORTH Microelectronics Research Group Univ. of Crete

2. Nitrides: Highlights Eliminate internal fields for better blue lasers
Superior p-type contacts
Integrated
HEMT on LED
Polarization engineering
on InAlGaN/GaN quantum wells
can give zero-field nitride
optoelectronic devices.
But, the optoelectronic quality
of InAlGaN has to be further
improved.
Cr/Au vs Ni/Au
LED fabrication
IST QN-Laser,
IST QN-Laser II
G. Dialynas et al. JAP 2008
F. Kalaitzakis, APL 2007
NMP GaNano

3. Novel optoelectronic devices: Highlights
Polariton LEDs and Lasers
Tunable
laser diodes
Piezoelectric laser diodes
p-side CB B1 B2 VB
Jth(111) < Jth(100)
T=235K
-S. Tsintzos, Nature 2008
-RT operation,
S. Tsintzos, APL 2009.
G. Deligeorgis, APL 2007
IST Tune-laser
APL 2002, APL 2003
20nm tuning at low T, 5nm tuning at 300K

4. Piezoelectric quantum dots: HighlightsV
InAs (211)B QDs
Reference QW
InAs QDs
G. Dialynas, JAP 2010 + e h
G. Dialynas, to be submitted

5. Piezoelectric quantum dots: Highlights
Very small FSS.
Promising for sources of entangled photons
Single dot spectroscopy
Single photon emission;
possibility for high-T operation
Anti-binding biexciton energy
S. Germanis, APL 2011

6. Project: III-V Nanowires for high efficiency Solar cells
Solar Innovation 2010 Award by
Commissariat a l’ Energie Atomique
3 year project
Why Nanowires for Solar Cells?
Potential for lower cost and high efficiency:
- enhanced light absorption,
less material utilization
- no need for lattice matching,
easier choice of substrate &
more freedom in heterostructure design
- direct path for charge transport
“nanowire solar cells”