Mitglied der Helmholtz-Gemeinschaft
Reinhard Carius and Uwe Rau
Nanostructures for Thin-film Silicon Solar Cells
Institute of Energy and Climate Research 5 - Photovoltaics -
Forschungszentrum Jülich, Germany
Device analysis and modeling Material
analysis
Deposition technologies
Large area deposition technologies
Module technology Module
analysis
In-situ-Control Material
modeling
Process modeling Material
design
Cell design and technology Material
development
Industrial product Industrially relevant processes Lab processes
IEK 5: complete chain of R&D for
thin film silicon solar cells
a-Si p-i-n µc-Si p-i-n
present type of thin film silicon solar cell
tandem solar cell
2-3 µm
our thin film silicon solar cell ‚work package‘
already includes several nanostructures
textured TCO
a-Si p-i-n
intermediate reflector µc-Si p-i-n
back-reflector glass substrate
2 µm
textured ZnO intermediate reflector
300 nm doped Si nanoparticles
intermediate reflector
photonic crystal
front glass ZnO a-Si:H (pin) metal contact
µc-Si:H (pin)
Plasmonic back contact
most recent developments:
thin film solar cells including nanoparticle absorbers
glass
ZnO:Al Ag ZnO:Al
glass
ZnO:Al ZnO:Al
Ag
our strategy (1)
Triple partners for a-Si/ c-Si solar cells
Advantages of nano-technology:
Tayloring of electrical, optical, and chemical properties
Preparation of nano-particles separated from cell separation no restrictions conc. growth
cost effective printing process nc-Si-layer
Mono-layer of
Highly absorbing nano-particles a-Si-layer
a-Si-layer
Complete replacement ? Starting point: well-established thin-film silicon-based technologies
Step 1: Replace functional elements by cheaper and/or better nano-approaches Step 2: Add new components by nano-technology
Step 3: Complete nano-technological solution
our strategy (2)
Si-Wafer solar cell
Starting point: well-established crystalline Si-based technologies
Step 1: Replace functional elements by cheaper and/or better nano-approaches Step 2: Add new components by nano-technology
Step 3: Complete nano-technological solution Tandem partners for Si-solar cells
Si QD in
SiO2/SiCMatrix
Si-Wafer solar cell Si QW in
SiO2 Matrix
Si-Wafer solar cell InGaN nanowires
SiGe nanowires
our strategy (2)
Si-Wafer solar cell
Starting point: well-established crystalline Si-based technologies
Step 1: Replace functional elements by cheaper and/or better nano-approaches Step 2: Add new components by nano-technology
Step 3: Complete nano-technological solution Tandem partners for Si-solar cells
Si QD in
SiO2/SiCMatrix
Si-Wafer solar cell Si QW in
SiO2 Matrix
Si-Wafer solar cell InGaN nanowires
SiGe nanowires
??? ???
Photovoltaics and nano-technology
light management absorption
charge separation (J
SC)
V
OC-Potential
charge extraction (FF) modules
Photovoltaics
photonics confinement nanomaterials
band gap engineering nano-composites
self-cleaning surfaces
nano-technology
NSOM
Photon management
simulation, modeling, theory
new functional materials
REM
nano-structural characterization
surface passivation structure relaxation
new methods
Si-Wafer solar cell
material synthesis
Our conclusions on
issues of nanotechnology in PV
Close collaboration between
nanoscience and photovoltaics required Support by theory essential
progress in photovoltaics needs nano-technology to support the functionality in particular
• low-mobility materials (short distances for charge separation) e.g., organic solar cells or dye solar cells
• unavailability of bulk materials with required physical properties e.g., effective materials (band gap, refr. index,..)
• physical impossibility to produce a required physical property by a bulk material, e.g., photonic crystals
