IRG4: Nanomaterials for Renewable Energy
IRG4 Leader
Gerardo [email protected]
EPSCRoRESEARCH IN PUERTO RICO
EPSCRoRESEARCH IN PUERTO RICO
Institute for Functional NanomaterialsUniversity of Puerto Rico http://www.ifn.upr.edu
IRG 4 Research Focus (revised in response to 2015 RSV)
The Interdisciplinary Research Group 4 aims to develop next-
generation photovoltaic devices based on nanostructured
ferroelectric semiconductors, taking advantage of the spontaneous
electric polarization of these materials for the separation of the
nascent electron-hole pairs as light is absorbed. To this end, IRG4
implements a comprehensive research agenda that integrates the
following key components:
(a) Synthesis and characterization of ferroelectric semiconductors
with narrow band gap in the visible region,
(b) Theoretical modeling studies to guide the experimental research
and provide fundamental understanding, and
(c) Fabrication and testing of prototype photovoltaic devices
based on narrow bandgap ferroelectric semiconductors.
EPSCRoRESEARCH IN PUERTO RICO
EPSCRoRESEARCH IN PUERTO RICO
Institute for Functional NanomaterialsUniversity of Puerto Rico http://www.ifn.upr.edu
IRG4 Senior Personnel
1. Zhongfang Chena,
2. Peter X. Fenga,
3. Luis F. Fonsecaa,
4. Pasquale Fulvioa,
5. Ram S. Katiyara,
6. Junqiang Lub,
7. Vladimir Makarova,
8. Carlos Marinb,
EPSCRoRESEARCH IN PUERTO RICO
EPSCRoRESEARCH IN PUERTO RICO
Institute for Functional NanomaterialsUniversity of Puerto Rico http://www.ifn.upr.edu
aUPR Rio PiedrasbUPR MayaguezcUPR HumacaodMetropolitan UniversityePolytechnic University
9. Gerardo Morella,
10.Ratnakar Palaia,
11.Luis Rosac,
12.Sushma Santapurie,
13.Mitkel Santiagod,
14.Maharaj Tomarb,
15.Josee Vedrinec,
16.Julian Veleva,
Strategic Partners: Dr. James F. Scott, St. Andrews University;
Dr. Evgeny Tsymbal, Dr. Peter Dowben, Dr. Alex Sinitskii and Dr. Barry Cheung,
University of Nebraska at Lincoln; Dr. Andrew Rappe, UPenn;
Dr. Wojciech M. Jadwisienczak, Ohio University
IRG4 Participants
Postdoctoral Fellows:
Dr. James S. Young, Dr. Muhammad Sajjad, Dr. Rajesh Katiyar
Graduate Fellows: Shalini Kumari, Yunlong Liao, Javier Palomino,
Radhe Agarwal, Tej Limbu, Omar Vega, Jose Hernandez, Daysi Diaz
Graduate Research Assistants: Bibek Thapa
Undergraduate Research Assistants: Jabril Vilmenay, Ernesto Espada
EPSCRoRESEARCH IN PUERTO RICO
EPSCRoRESEARCH IN PUERTO RICO
Institute for Functional NanomaterialsUniversity of Puerto Rico http://www.ifn.upr.edu
EPSCRoRESEARCH IN PUERTO RICO
EPSCRoRESEARCH IN PUERTO RICO
Institute for Functional NanomaterialsUniversity of Puerto Rico http://www.ifn.upr.edu
Ferroelectric Photovoltaics
Schematic illustration of ferroelectric photovoltaic effect
Crystal polarity creates
microscopic electric fields across
the domains as depicted in figure
Responsible for separation of
photo-generated excitons into free
charges
Transport of free charges to
contact with minimum
recombination rate
Ferroelectric materials can achieve high open circuit voltages (Voc), unlike a p-n junction
photovoltaic cell where Voc is constrained by optical band gap of absorber material.
FE-PV vs p-n junctions
EPSCRoRESEARCH IN PUERTO RICO
EPSCRoRESEARCH IN PUERTO RICO
Institute for Functional NanomaterialsUniversity of Puerto Rico http://www.ifn.upr.edu
Limitations:
• High band gap > 2.7 eV
• Low short circuit current ~ nA/cm2
• Low conversion efficiency less than ~ 0.01%
Opportunities:
• No conventional p-n junction required
• Open Circuit Voltage not limited by the material band gap
• No degradation of device performance in the 273 100 K range
• Abundant precursor materials
Ferroelectric Photovoltaics
Strategies:
• Band gap can be lowered to ~ 2 eV by doping and substitutions
• Control of defects to obtain photocurrents in the ~ mA/cm2 range
Enhanced Photoresponse in
BiFeO3/SrRuO3 Heterostructures
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EPSCRoRESEARCH IN PUERTO RICO
Institute for Functional NanomaterialsUniversity of Puerto Rico http://www.ifn.upr.edu
Journal of Alloys and Compounds 609, 168, 2014.
short circuit current density ~63µA/cm2
open circuit voltage of ~0.08 V
rhombohedra R3c space group
7
Effect of Poling on the Photovoltaic Properties of
Highly Oriented BiFeO3/SrTiO3Thin Films
EPSCRoRESEARCH IN PUERTO RICO
EPSCRoRESEARCH IN PUERTO RICO
Institute for Functional NanomaterialsUniversity of Puerto Rico http://www.ifn.upr.edu
Integrated Ferroelectrics, 157:168–173, 2014 8
Switchable Photovoltaic Effect in Bilayer
Graphene/BiFeO3/Pt Heterostructures
EPSCRoRESEARCH IN PUERTO RICO
EPSCRoRESEARCH IN PUERTO RICO
Institute for Functional NanomaterialsUniversity of Puerto Rico http://www.ifn.upr.edu
Applied Physics Letters 105, 142902, 2014.
PFM images
9
Ferroelectric Photovoltaic Effects in
Doubly Substituted BLFTO Thin Films
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EPSCRoRESEARCH IN PUERTO RICO
Institute for Functional NanomaterialsUniversity of Puerto Rico http://www.ifn.upr.edu
Current density as a function of
applied bias voltage for the
Pt/BLFTO/ZnO:Al heterostructures
Applied Physics Letters 106, 082903, 2015.
[Bi0.9La0.1][Fe0.97Ta0.03]O3 (BLFTO)
ISC ~1.35 mA/cm2
VOC ~0.20V
Si-modified BiFeO3 Ferroelectric PV
for Light Harvesting Windows
EPSCRoRESEARCH IN PUERTO RICO
EPSCRoRESEARCH IN PUERTO RICO
Institute for Functional NanomaterialsUniversity of Puerto Rico http://www.ifn.upr.edu
Applied Physics Letters 107, 062902 , 2015.
[BiFe0.95Si0.05O3] (BFSiO)
Graphene
ISC 0.75 mA
VOC 0.45 V
ITO
ISC 0.63mA
VOC 0.35V
Band Gap ~ 2.2
Power conversion
efficiencies:
A: 3.64%
B: 1.96%,
Graphene Transparent Electrodes
EPSCRoRESEARCH IN PUERTO RICO
EPSCRoRESEARCH IN PUERTO RICO
Institute for Functional NanomaterialsUniversity of Puerto Rico http://www.ifn.upr.edu
DRM 51, 34, 2015; AIP 6, 35319, 2016
HFCVD Bilayer Graphene
EPSCRoRESEARCH IN PUERTO RICO
EPSCRoRESEARCH IN PUERTO RICO
Institute for Functional NanomaterialsUniversity of Puerto Rico http://www.ifn.upr.edu
Limitations:
• High band gap > 2.7 eV
• Low short circuit current ~ nA/cm2
• Low conversion efficiency less than ~ 0.01%
Ferroelectric Photovoltaics
Accomplishments:• Band gap ~ 2.2 eV
• Short circuit current ~ mA/cm2
• Conversion efficiency less than ~ 3%
Opportunities:
• No conventional p-n junction required
• Open Circuit Voltage not limited by the material band gap
• No degradation of device performance in the 273 100 K range
• Abundant precursor materials
IRG4: Peer-Reviewed Publications
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EPSCRoRESEARCH IN PUERTO RICO
Institute for Functional NanomaterialsUniversity of Puerto Rico http://www.ifn.upr.edu
1. ACS Applied Materials and Interfaces 6, 13815, 2014.
2. Angewandte Chemie International Edition 54, 3112-3115, 2015.
3. Applied Physics Letters 105, 072908, 2014.
4. Applied Physics Letters 105, 142902, 2014.
5. Applied Physics Letters, 105, 172904, 2014.
6. Applied Physics Letters 106, 082903, 2015.
7. Carbon 75, 113, 2014.
8. J. Physical Chemistry C 118, 25051–25056, 2014.
9. Diamond and Related Materials 51, 34, 2015.
10. Electrochimica Acta 147, 392-400, 2014.
11. Integrated Ferroelectrics 157, 168, 2014.
12. ISRN Electrochemistry, 359019, 2014.
13. Journal of Alloys and Compounds 641, 99-105, 2015.
14. Journal of Alloys and Compounds, 609, 168-172, 2014.
15. Journal of Applied Physics 115, 84102, 2014.
16. Journal of Nano Energy and Power Research 3, 1-4, 2015.
17. Journal of Nanotechnology, 381273, 2014.
18. Phys. Chem. Chem. Phys., 17, 2160-2168, 2015.
19. Physica Status Solidi C 12, 413-417, 2015.
20. Royal Society of Chemistry Advances 5, 11240-11247, 2015.
Density Functional Theory of Bi1-xKxFeO3
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EPSCRoRESEARCH IN PUERTO RICO
Institute for Functional NanomaterialsUniversity of Puerto Rico http://www.ifn.upr.edu
Spin_down
Spin_up
K doping produces a significant reduction in bandgap and leakage current
EPSCRoRESEARCH IN PUERTO RICO
EPSCRoRESEARCH IN PUERTO RICO
Institute for Functional NanomaterialsUniversity of Puerto Rico http://www.ifn.upr.edu
• We encourage the focus on the basic research on
ferroelectric materials for energy harvesting. It is a field
where this group can make significant impact since
few other groups work in this area.
• We would encourage this team to develop the basic
understanding of the physics of carrier transport in
these ferroelectric materials and the dependence of
built‐in fields, domain size, interface and contacts.
• The fundamental understanding of these effects would
significantly enhance the value of this research.
2016 EAB Comments on IRG4
EPSCRoRESEARCH IN PUERTO RICO
EPSCRoRESEARCH IN PUERTO RICO
Institute for Functional NanomaterialsUniversity of Puerto Rico http://www.ifn.upr.edu
Thank you for your attention
IRG 4: Nanomaterials for Renewable Energy