Group IV Nano Optoelectronics: Si Nano Optoelectronics: Recent - - PowerPoint PPT Presentation
Group IV Nano Optoelectronics: Si Nano Optoelectronics: Recent Developments based on Bottom-Up Approaches Recent Developments based on Bottom-Up Approaches The 6 th US-Korea Forums on Nanotechnology: Nanoelectronics and its Integration with
US-Korea Nano-Forum 2009 POSTECH, Nano Device Materials and Physics Lab
April 29. 2009 Moon-Ho Jo
Pohang University of Science and Technology (POSTECH)
US-Korea Nano-Forum 2009 POSTECH, Nano Device Materials and Physics Lab
(Liquid) (Liquid) (Solid) (Solid) SiH SiH4 2H 2H2 SiGe GeH GeH4 (Vap (Vapor)
US-Korea Nano-Forum 2009 POSTECH, Nano Device Materials and Physics Lab
the individual NW level level
NW arrays
US-Korea Nano-Forum 2009 POSTECH, Nano Device Materials and Physics Lab
20 nm 0.209nm 2 nm 20 nm 20 nm 0.209nm 2 nm 0.209nm 2 nm 2 nmSiO2/Si
[Visible] [Near Infrared]
1.55μm 1.35μm
[Ultraviolet]
Nature Phys., Accepted (2009) Nano Lett., Accepted (2009)
Nano Lett. 6 2679 (2006)
Nanowire Electronics Nanowire Growth
Submitted, (2009) Nano Lett. 8 431 (2008)
Nano Lett. 4 1547 (2004) Nano Lett. 8 4523 (2008)
Nano Lett, 6 2014 (2006)
Nano Device Materials & Physics Laboratory
Nanowire Photonics/Optoelectronics/Plasmonics
US-Korea Nano-Forum 2009 POSTECH, Nano Device Materials and Physics Lab
the visible with quantum efficiencies in excess of 10%.
Photoluminescence in NIR to UV from Si quantum dots (QD) of various size*
T.Y. Kim et al., Appl. Phys. Lett. 85 85, 5355 (2004) Lorenzo Pavesi and David J. Lockwood, Materials Today, Jan. 26, 2005
Nano Si Photonics
US-Korea Nano-Forum 2009 POSTECH, Nano Device Materials and Physics Lab
Nano Silicon Photovoltaics
M.C. Beard, Nano. Lett. 7, 2506 (2007)
than twice the band gap.
US-Korea Nano-Forum 2009 POSTECH, Nano Device Materials and Physics Lab
Si:Ge Nano Crystals: The model system for continuously varying lattices and energy band-gaps at the nanometer scale
Si:Ge Nanowire Optoelectronics
US-Korea Nano-Forum 2009 POSTECH, Nano Device Materials and Physics Lab
(Li (Liqui quid) d) (S (Solid)
SiH4, GeH4 2H2 Si
(Vapor) (Vapor)
Conventional VLS-CVD Nanowire Growth
Growth of Single-Crystalline Si1-xGex Nanowires
2μm 5nm
Chang-Beom Jin et al., Appl. Phys. Lett. 88 88, 193105 (2006) Jee-Eun Yang, et al., Nano Lett. 6, 2679 (2006)
US-Korea Nano-Forum 2009 POSTECH, Nano Device Materials and Physics Lab
Band-Gap Modulation in Si1-xGex Nanowires
with increasing Ge content.
Bohr radius of 4.7nm for Si and 17.7nm for Ge)
Jee-Eun Yang et al., Nano Lett. 6, 2679 (2006)
US-Korea Nano-Forum 2009 POSTECH, Nano Device Materials and Physics Lab
532 nm Laser
Diffraction limit : . . A N k R λ × = Δ k : technical constant (~0.61)
= 360 nm, 650 nm
measurements of “spatially resolved” electroluminescence and photoconductivity.
counting.
Nano Optoelectronics Laboratory
US-Korea Nano-Forum 2009 POSTECH, Nano Device Materials and Physics Lab
Cheol-Joo Kim et al., Nano Lett., Accepted (2009)
Intra-Nanowire p-n diode
Photocurrent in Si Nanowire p-n diode
D S D S
n p
Vsd = -5.0 V Vsd = -2.5 V Vsd = 0.0 V Vsd = 2.5 V Vsd = 5.0 V nA 100
hν e h Drai Drain Sourc
2um n p
Vb
US-Korea Nano-Forum 2009 POSTECH, Nano Device Materials and Physics Lab
Confocal Raman Spectro-Microscopy
Raman Scattering in Si1-xGex Semiconductors
Jee-Eun Yang et al., Appl. Phys. Lett., 92 92, 263111 (2008) (with Prof. Zee Hwan Kim, Korea Univ. )
US-Korea Nano-Forum 2009 POSTECH, Nano Device Materials and Physics Lab
is even more pronounced at lower light intensity.
gain mechanism, originating from the surface state filling. Ge Nanowire Photodetector
10
2
10
3
10
4
10
5
10
6
10
10
10
10
0.32 0.87
ΔG (S)
Intensity (W/cm
2) Ge NW
Si NW
0.73
10
2
10
3
10
4
10
5
10
6
10
10
10
PC Gain Intensity (W/cm
2) Ge NW
Si NW Photodiode 532 nm XY piezo-scanner A Vsd Objective Lens (N.A. =0.5) Laser X Y Vg Si NW or Ge NW
Cheol-Joo Kim et al., Nano Lett., Accepted (2009)
US-Korea Nano-Forum 2009 POSTECH, Nano Device Materials and Physics Lab
10 μm
Nanowire Substrate
50 nm 2 nm
(a) (b) (c)
20 μm
Vertical Growth by Epitaxy on (111) Si Substrates
Cheol-Joo Kim et al., Appl. Phys. Lett., In Press (2009) Kibum Kang et al., Adv. Mater. 20 4684 (2008)
Epitaxial NW Growth for Ordered Arrays
US-Korea Nano-Forum 2009 POSTECH, Nano Device Materials and Physics Lab
Substrate: SiO Substrate: SiO2(100 nm)/Si(111)- (100 nm)/Si(111)-p Metal deposition Metal deposition & PS lift-off & PS lift-off SiO SiO2 Dry & y & W Wet etchi t etching Au deposition Au deposition & Lif & Lift-off
Growth of Si NWs Growth of Si NWs Reactive ion etching Reactive ion etching Si(111) Si(111) SiO SiO2 Metal Metal PS PS Au Au Epitaxial NW Growth for Ordered Arrays
(I) PS Nanosphere (I) PS Nanosphere Lithography Lithography
US-Korea Nano-Forum 2009 POSTECH, Nano Device Materials and Physics Lab
Si Nanowire Arrays from Au-Catalyst Patterns by Nanosphere Lithography
Templated-Assisted NW Growth for Ordered Arrays
US-Korea Nano-Forum 2009 POSTECH, Nano Device Materials and Physics Lab
(1) Si nanowire vs. NiSi nanowire
Si NW Li-Battery at POSTECH
Anode Anode
LOAD
Charge Charge Discharge Discharge
Potentiostat/Galvanostat
Si NW Anode Li Cathode Electrolytes
US-Korea Nano-Forum 2009 POSTECH, Nano Device Materials and Physics Lab
ANO ANO ANO D
EVICE E EVI EVICE E M
ATERIALS ATERIALS ATERIALS & Physics L
AB AB AB
Jee-Eun Yang Hyun-Seung Lee Cheol-Joo Kim Kibum Kang