Lab'InSight Surface Treatments & Solar Energy - Focus on the Photovoltaic Electricity Sector - 21.11.2013

1. Solid-state Physics,
Interfaces and Nanostructures
Department of Physics
University of Liège
Watching the Lab’s video
Prof. Ngoc Duy NGUYEN
Head of Laboratory
Lab’Insight ‘Surface Treatments and Solar Energy’
SPIN
SOLID- STATE PHYSICS, INTERFACES AND NANOSTRUCTURES
Brussels – 21st November 2013
1

2. Fields of expertise and industrial
targets
Fields of expertise
• Material characterizations
 Electrical and optical measurements
• Electron device simulations
 Physical interpretation of device characteristics
• Atomistic simulations
 Prediction and optimization of material properties
Industrial applications fields
• Quality control, in-line monitoring
• Defect assessment
• Device characterization
Brussels – 21st November 2013
2

3. sition of CIGS and CdT coatings.
e
pics
allographic direction, respectively, for the involved ZnOnanowire
218
sample and for a randomly oriented wurtzite ZnOsample given by
heJ
oint C
ommittee for P
owder Diffraction S
tandard (J P ) values
C DS
24]; and N corresponds to the number of considered peaks. In our
case, five peaks should becrysconsidered so that N=5. A randomly oried intensities of the <hkl>
219
220
221
222
Applied research projects
CIS/CIGS materials for
, for the involved ZnOnanowire
d wurtzite ZnO sample given byfilm photovoltaics
thin
223
224
220
221
raction S
tandard (J PDS values
C
)
mber of considered peaks. In our
ed so that N=5. A randomly ori-
222
Material characterization
Device simulation
Electrical and opto-electrical
characterization of thin film
semiconducting heterostructures
223
224
TCO/CdS
CIGS
Mo
Aim
Defect assessment
Substrate
CLE IN PRESS
 Identify defect signatures in electrochemical
impedance spectroscopy
2. Experimental
Cu(In,Ga)Se2-based layer stack
 Correlate with material quality
2.1. F
luorine-doped tin oxide thin films
as thin-film photovoltaic cell
 Implement measurement as an in-line
All ZnO depositions were performed onto FTO thin film with a
thickness of 250 nm. FTOthin films were grown on glass substrates monitoring tool
at 410 Cby atmospheric spray pyrolysis from achemical precursor

consisting of 0.16 M tin chloride pentahydrate 98%(S
igma-Aldrich) Provide feedback to process steps
Materials S
cience and E
ngineering Bxxx (2011) xxx–xxx
110
111
112
113
◦
114
115
and 0.04 M ammonium fluoride 98%(S
igma-Aldrich) in amethanolic solution. The S
heet resistance of FTOthin films is about 10 per
square while their overall transmittance with glass equals nearly
85%in the visible range.
b) top view S M image, (c) TE image of a single nanowire and ISCHE SCOP ®
E
M
Offline F (d) XR diagram,
RD E
CONT 4000- P
I
DP
2.2. ZnOnanowire growth by chemical bath deposition
116
117
118
119
Brussels – 21st November 2013
120
3

4. Applied research projects
Material characterization
Emerging transparent conductive materials
as electrodes for solar cells
Aim
Investigation of the percolation mechanism
in metallic nanowire networks
Encapsulated Ag nanowire network
as transparent conductive material
 Understand electrical conductivity and
optical transmittance
 Compute collection efficiency
 Solve thermal stability issue
 Integrate in dye-sensitized solar cells
Brussels – 21st November 2013
4

5. Applied research projects
Modeling
Atomistic simulations of nanostructures
(ab initio)
Aim
Optimisation of photovoltaic properties
Light-induced charge separation in
a Si-Ge pyramidal wire (2 nm
diameter)
 Provide model structures (compositions,
geometries)
 Provide spectral fingerprints
 Estimate the effect of the environment (i.e.
effect of ligands and solvant on chemical
stability and spectral properties)
Brussels – 21st November 2013
5

6. Special equipments
Brussels – 21st November 2013
6

7. Services provided to companies
Examples
→
→
→
→
Consultancy service in electrical and optical characterization of thin films
Expertise on impedance spectroscopy
Device simulation works
Experimental development in semiconductor metrology for industry-oriented
long-term applied projects
→ On-demand calculations (collaboration-based) of atomistic structures,
electronic and optical properties
→ Training of scientists
Brussels – 21st November 2013
7

8. Contact information
University of Liège|Department of Physics
Solid-state Physics, interfaces and nanostructures
Institut de Physique (B5a), Allée du Six Août 17, 4000 Liège (Sart-Tilman)
http://www.spin.ulg.ac.be
Prof. Ngoc Duy NGUYEN
Chargé de cours
ngocduy.nguyen@ulg.ac.be, phone : +32 4 366 3604
Dr. Jean-Yves RATY
Senior Research Associate FRS-FNRS
jyraty@ulg.ac.be, phone : +32 4 366 3747
SPIN
SOLID- STATE PHYSICS, INTERFACES AND NANOSTRUCTURES
Brussels – 21st November 2013
8