renewable energy materials research science and engineering …remrsec... · 2013. 11. 15. ·...
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What is Nanionics? • Nanoionics centers on the manipulation of space
charge at ionic interfaces or junctions to control ionic conduction.
Our Vision:
• Explore/exploit nanoionic effects to create the
next generation of ionic materials/devices.
Renewable Energy Materials Research Science and Engineering Center (REMRSEC) NSF MRSEC DMR-0820518
P. C. Taylor, R. T. Collins, A. Herring, C. Koh. B. Moskal (Co-PI’s)
IRG2: Advanced Membranes for Energy Applications
Membranes play a critical role in renewable energy
technologies
Current membranes are a weak link in many applications
A fundamental understanding of ionic transport is
essential to make transformative changes in membrane
materials
IRG1: Materials for Next Generation Photovoltaics
PV electric power today is more expensive than coal
Incremental changes in materials will not get us where we need to go
A fundamental understanding of nanostructured and other
PV materials is essential to make transformative changes in
solar panels This goal requires understanding and controlling carrier
relaxation rates in quantum confined systems
Seed Project: Clathrate Hydrates and Silicon
Clathrates for Storage of Fuels
Current storage materials are a weak link in all applications
A fundamental understanding of the incorporation of
guest molecules in clathrate hydrates is essential to
make transformative changes in these storage materials
• Outreach to students and the community
• Promotion of diversity in faculty, students, and
future students
REMRSEC Vision
Research and Engineering
• Innovative and transformative research and
engineering on materials for renewable energy
applications
Human Resource Development
• Education of the next generation of renewable
energy professionals
Goals: Education, Human Resources, and Diversity
Prepare undergraduate and graduate students to embark on
careers in
renewable energy fields
Provide undergraduate and graduate students with research
experiences in renewable energy
Expose K-12 teachers and students to concepts of renewable
energy
Improve the recruitment and retention of female and minority
undergraduate and graduate students and faculty
Accomplishments: Education, Human Resources, and Diversity
Development of Renewable Energy Minor
Successful REU program in renewable energy
Successful K-12 teacher workshop on renewable energy curricula
First joint RFEMRSEC-NREL hire
c-Si
Collect Particles onto a Substrate
Control Particle Size & Distribution
Growth of 3-D Superlattice Structures
Synthesize Nanoparticles
Embed Particles in an Oxide Matrix
Decouple Nanocrystal Synthesis from Matrix
Encapsulation Process
2000 2100 2200 2300
2234 cm-1
(SiH(O3))2168 cm
-1
(SiH2(O
2))
2135 cm-1
(Surface SiH3)
2102 cm-1
(Surface SiH2)
Tra
nsm
ittan
ce (
a.u.
)
Wavenumber (cm-1)
2072 cm-1
(Surface SiH)
0 200 400 600 800
Ram
an In
tens
ity (
a.u.
)
Raman Shift (cm-1)
509 cm-1
Si phonon peak
Size Control of Si NCs
Blue shift observed due to
decrease in Si NC core size
due to oxication
600 700 800 900 1000
PL
In
ten
sity (
a. u
.)
Wavelength (nm)
after 24 hrs
as-synthesized
(eV)2.2 2 1.8 1.6 1.4 1.2
600 700 800 900 1000
PL
In
ten
sity (
a. u
.)
Wavelength (nm)
1 W
3 W
10 W
15 W
Decreasing
RF Power
(eV)2.2 2 1.8 1.6 1.4 1.2
Change in PL peak position
with rf power: Si NC size
decreases with increasing
power
UV
off
UV
on
SiOx
Organic Photovoltaics
• ZnO nanowire/polymer bulk heterojunctions OPVs
• Interface functionalization and device optimization
• New organic absorbers (dendrimers) and acceptors (trimetaspheres)
• Manufacturable deposition techniques – inkjet, spray
without
ODT
with
ODT
Addressing Ionic Transport via Nanoionics
“Superionoc” Hybrid Overview
“Ionic hybrids” - Novel composite ionic
materials based on combination of proton
conducting oxides and hydrogen permeable
metals
Work function difference between the oxide
and metal creates space charge layer
Enhance proton conductivity
Schematic diagram of
diffusion of protons in the
SCL
Ionic Transistor: Proof-Of Concept
0
20
40
60
80
100
120
140
160
-0.5 0.5 1.5 2.5
So
urc
e-D
rain
Cu
rre
nt
Os
cil
lati
on
(p
A)
Applied Source-Drain Voltage (V)
Vg = 0.608
Vg = 0.204V
Vg = 0.396V
Macro-scale room temperature ionic FET has been built
Modulation of ionic conductivity analogous to electronic
FET
Provides proof-of-concept
Utilize to verify/study the effects of nanoionic space
charge phenomena
Research plan for Micro-scale solid state ionic FET
Modeling