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QESSTnewsletter • summer 2015, volume 4

researchhighlights Honsberg Wins Prestigious Cherry Award from IEEE

QESST Director, Christiana Honsberg, Professor of Electrical Engineering in the School of Electrical, Computer and Energy Engineering (ECEE) and Director of the Solar Power Laboratory at Arizona State University, received the William R. Cherry Award at the Photovoltaics Specialists Conference (PVSC), hosted by the IEEE, on Monday, June 15, 2015.

Professor Honsberg received the Cherry Award in recognition of her multiple contributions to the advancement of photovoltaics. Her most notable contributions include the pioneering of advanced PV concepts ranging from the development of a generalized thermodynamic theory for determining efficiency limits of solar cells to making seminal advances in the understanding of intermediate band, interband, and quantum well approaches.

Honbserg also is a co-inventor of the so-called “Very High Efficiency Solar Cell (VHESC)” that combines optical/solar cell architectures that produced a sum-of-the efficiencies result of 42.8%. She has contributed to the advancement of III-Nitride solar cells, and is responsible for inventing and licensing of methods to produce high performance Si solar cells.

Additionally, Professor Honsberg is a co-developer of the popular PV CDROM educational online course that now is widely used in solar cell education at universities around the world. Honsberg serves as Director and Lead Investigator to the first U.S. multi-Institutional Engineering Research Center (ERC) on Photovoltaics (Quantum Energy and Sustainable Solar Technologies) that is jointly supported by the U.S. National Science Foundation and the U.S. Department of Energy, and where she leads and coordinates the ERC’s R&D efforts across some 30 national and international academic and industry partners, with a focus on enabling solutions to harness solar power in economically more viable and sustainable ways.

important datesWorkshop on Crystalline Silicon Solar Cells and Modules: Materials and ProcessesJuly 26-29, 2015Keystone, Colorado

QESST Summer Programs Closing SessionAugust 7, 2015Engineering Research Center Building, Rooms 106, 189, Gallery

ASU Fall Kick-off MeetingAugust 19th

Engineering Research Center Building, Room 189

All QESST Vidyo ConferencesAugust 31st

September 21st

October 5th

October 19th

November 2nd

November 16th

December 7th

January 4th

February 1st

February 15th

March 21st

April 4th

April 18th

ASU HomecomingNovember 14, 2015ASU Tempe Campus

Quantum Energy and Sustainable Solar TechnologiesAN NSF-DOE ENGINEERING RESEARCH CENTER

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Achievements earn Zhang IEEE Fellow status

Outstanding accomplishments in engineering have earned Yong-Hang Zhang honored status in one of the world’s most prominent professional organizations. IEEE Fellow is a distinction reserved for the most prestigious IEEE members and is conferred by the Board of Directors upon engineers with an extraordinary record of accomplishments in their field. Zhang is being recognized for his contributions to molecular beam epitaxy growth technology, infrared lasers and photodetectors.

Richard R. King to join ASU, QESST

Richard R. King received his Ph.D. and M.S. in electrical engineering from Stanford University, and his B.S. degree in physics, also from Stanford. Dr. King is joining Arizona State University in August 2015 as Professor in the School of Electrical, Computer, and Energy Engineering. Prior to joining ASU, he was Principal Scientist and Technical Fellow responsible for photovoltaic cell R&D at Spectrolab, Inc. His research on photovoltaics over the last 30 years has explored metamorphic III-V materials, high-lifetime back-contact silicon solar cells, dilute nitride GaInNAs(Sb), ordered and disordered (Al)GaInP, characterization of defects and recombination in compound semiconductors, high-transparency tunnel junctions, and integration into high-efficiency multijunction solar cells with 3 to 6 junctions. In 2006, this work led to the first solar cell of any type to reach over 40% efficiency. Dr. King is the recipient of the 2010 William R. Cherry Award given by the IEEE for “outstanding contributions to photovoltaic science and technology.” He is a strong supporter of photovoltaics education, and is a co-founding editor of the IEEE Journal of Photovoltaics. Dr. King served as general chair for the 40th IEEE Photovoltaic Specialists Conference in 2014. He looks forward to joining ASU in the fall!

Bakkaloglu wins Best Paper Award

Bertan Bakkaloglu, ECEE Professor of Electrical, Computer and Energy Engineering (ECEE) at ASU, received the IEEE VTS 2014 Best Paper Award for “A Built-In Self-Test Technique for Load Inductance and Lossless Current Sensing of DC-DC Converters.” Bakkaloglu shares this award with Sule Ozev, Associate Professor of ECEE at ASU.

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QESST Scholar Awards at PVSC

Congratulations to the following QESST Scholars for their recognition at the recent IEEE PVSC Conference in New Orleans:

Robert Lovelett won Best Student Paper (Area 4) for “A stochastic model for Cu(InGa)(SeS)2 absorber growth during selenization/sulfization”

Jaewon Oh won Best Student Paper (Area 11) for “Quantum Efficiency Loss after PID Stress: Wavelength Dependence on Cell Surface and Cell Edge”

Zhenshan “Jason” Yu (not pictured) won Best Poster (Area 3) for “PVMirror: A Tandem Solar Cell that Collects Diffuse Light”

QESST Scholars Robert Lovelett (left) and Jaewon Oh (right) with their Best Student Paper Awards at the 42nd IEEE PVSC Conference in New Orleans in June 2015.

QESST ERC Hosts Successful Year 4 Review by NSF and DOE

The QESST ERC hosted representatives of the NSF and DOE for a successful yearly review meeting on May 5-6, 2015, which included more than 150 faculty, scholars, and staff from seven different universities across the country. More than 45 students presented posters about their work.

The NSF/DOE site visit team recommended continued support for the QESST ERC with its next increment of funding, expected by August 1, 2015. Allocations will be made to the appropriate grant accounts once the award letter has been received by ASU.

Dimitris Pavlidis, Site Visit team member, discusses research work with QESST Scholars Hal Emmer and Sisir Yalamanchili from Caltech.

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QESST at 42nd IEEE Photovoltaic Specialists Conference - June 14-19, 2015, New OrleansQESST was very well represented at the 42nd IEEE PVSC Conference in New Orleans. The following papers were presented by QESST Faculty and Scholars.

“Designing and Prototyping the Polyhedral Specular Reflector, a Spectrum-Splitting Module with Projected >50% Efficiency” Carissa N. Eisler, Pilar Espinet, Cristofer A. Flowers, Sunita Darbe, Emily C. Warmann, John Lloyd, Michelle Dee, Harry A. Atwater

“GaP/Si Heterojunction Solar Cells” Christopher T Chen, Rebecca Saive, Hal S Emmer, Shaul Aloni, Harry A Atwater

“Resonant dielectric high-contrast gratings as spectrum-splitting optical elements for ultrahigh efficiency (>50%) photovoltaics” Sunita Darbe and Harry A. Atwater

“Single Crystal Cu2O Photovoltaics by the Floating Zone Method” Stefan T. Omelchenko, Yulia Tolstova, Samantha S. Wilson, Harry A. Atwater, Nathan S. Lewis

“Fabrication and Characterization of ZnSnxGe1-xN2Alloys for Light Absorbers“ Amanda Shing, Naomi Coronel, Nathan S. Lewis, Harry A. Atwater

“Molecular Beam Epitaxy of Cu2O Heterostructures for Photovoltaics” Yulia Tolstova, Samantha S. Wilson, Stefan T. Omelchenko, Nathan S. Lewis, Harry A. Atwater

“3 µm Thick GaSb Membrane Diodes Integrated with CVD Diamond Heat Spreaders for Thermally Managed TPV Systems” Emma J. Renteria, Sadhvikas J. Addamane, Darryl M. Shima, Christopher P. Hains, Ganesh Balakrishnan

“High Temperature Characterization of GaAs Single Junction Solar Cells“ Aymeric Maros, Srikanth Gangam, Justin Smith, Stephen Goodnick, Mariana Bertoni, Christiana B. Honsberg

“Evaluation of metal oxides prepared by reactive sputtering as carrier-selective contacts for crystalline silicon solar cells” Mathieu Boccard, Laura Ding, Priyaranga Koswatta, Mariana Bertoni, Zachary Holman

“Correlation between grain composition and charge carrier collection in Cu(In,Ga)Se2 solar cells” Bradley West, Sebastian Husein, Michael Stuckelberger, Barry Lai, Jorg Maser, Benjamin Stripe, Volker Rose, Harvey Guthrey, Mowafak Al-Jassim, Mariana Bertoni

“Innovative Methods for Low-Temperature Contact Formation For Photovoltaics Applications” April M Jeffries, Avinash Mamidanna, Jacob Clenney, Laura Ding, Owen Hildreth, Mariana Bertoni

“Latest Developments in the X-Ray Based Characterization of Thin-Film Solar Cells” Michael Stuckelberger, Bradley West, Sebastian Husein, Harvey Guthrey, Mowafak Al-Jassim, Rupak Chakraborty, Tonio Buonassisi, Jörg M. Maser, Barry Lai, Benjamin Stripe, Volker Rose, Mariana Bertoni

“Flexible silicon heterojunctions solar cells and modules” André Augusto, Luc Reboulet, Stanislau Y Herasimenka, Stuart Bowden

“A Kinetic Monte Carlo Study of Transport in Silicon Heterojunction Solar Cells” Pradyumna Muralidharan, Dragica Vasileska, Stephen M Goodnick, Stuart Bowden

“Electrical Characterization of Thermally-formed Nickel Silicide for Nickel-Copper Plated Solar Cell Contacts” Joseph Karas, Sangpyeong Kim, Lynne Michaelson, Krystal Munoz, Tom Tyson, Stuart Bowden

“Application of Flexible Glass to Prevent PID in PV Modules” Jaewon Oh, GovindaSamy TamizhMani, Stuart Bowden, Sean Garner

“Quantum Efficiency Loss after PID Stress: Wavelength Dependence on Cell Surface and Cell Edge” Jaewon Oh, Stuart Bowden, GovindaSamy TamizhMani, Peter Hacke

“Modeling of Silicon Heterojunction Solar Cells” Pietro Luppina, Paolo Lugli, Stephen Goodnick

“High Temperature InGaN Solar Cell Modeling” Y. Fang, D. Vasileska, C. Honsberg, S.M. Goodnick

“Enhanced forward scattering and transmitted light diffraction with a low aspect-ratio silicon nanopillar for high efficiency thin Si solar cell” Jeayoung Choi, Natasa Vulic, Stephen Goodnick, Christiana Honsberg

“Influence of High Growth Rate on GaAs-based Solar Cells Grown by Metalorganic Chemical Vapor Deposition” Chaomin Zhang, Yeongho Kim, Chris Ebert, Nikolai Faleev, Christiana B. Honsberg

“Effect of InGaAsSb capping layer on the structural properties of InAs/InGaAsSb quantum dots” Yeongho Kim, Nikolai Faleev, Christiana B. Honsberg

“Large-Area III-Nitride Double-Heterojunction Solar Cells with Record-High In-content InGaN Absorbing Layers” Chloe A. M. Fabien, Brendan P. Gunning, Joseph J. Merola, Evan A. Clinton, W. Alan Doolittle

“The Minority Carrier Lifetime Measurements: An Electrical Passivation Study” Meixi Chen, James Hack, Abhishek Iyer, Robert Opila

“Defect-Induced Performance Enhancement in Moderately Dislocated (1E8cm-2) GaAs Tunnel Diodes” Kaveh Shervin, Akhil Mehrotra, Alex Freundlich

“Real-time Growth Assessments of Size Orientation and Facet Asymmetries of Self-assembled Quantum Dots” Manori V. Gunasekera, Alexandre Freundlich

“Interface Engineered Wetting Layer Free InAs QDs on GaAs(001)” Manori V. Gunasekera, Dinghao Tang, Alexandre Freundlich, David A. Smith, Irene Rusakova

“Rapid Sub-Wavelength Texturing for III-V Solar Cells by Laser Interference Lithography and Selective Wet Etching” Wei Wang, Alexandre Freundlich

“Carrier-Selective Contacts in Silicon Solar Cells” Priyaranga Koswatta, Mathieu Boccard, Zachary Holman

“A New Expression for Intrinsic Fill Factor of Silicon Solar Cells” Mehdi Leilaeioun, Zachary Holman

“PVMirror: A Tandem Solar Cell that Collects Diffuse Light” Zhengshan J. Yu, Kathryn C. Fisher, Zachary C. Holman

“A stochastic model for Cu(InGa)(SeS)2 absorber growth during selenization/sulfization” Robert J Lovelett, William N Shafarman, Robert W Birkmire, Babatunde A Ogunnaike

“The Role of the Intrinsic Zinc Oxide Layers on the Performance of Wide-bandgap (AgCu)(InGa)Se2 Thin-Film Solar Cells” Uwadiae Obahiagbon, Christopher P. Thompson, William N. Shafarman, Steve S. Hegedus

“Characterization and numerical modeling of Cu(In,Ga)(S,Se)2 solar cells” Christopher P Thompson, William N. Shafarman, Dongho Lee

“Bandgap gradients in (Ag,Cu)(In,Ga)Se2 thin film solar cells deposited by three-stage co-evaporation” Christopher P Thompson, Lei Chen, William N Shafarman, Jinwoo Lee, Shannon Fields, Robert W Birkmire

“VOC Enhancement of Sub-micron CIGS Solar Cells by Sulfization of the Mo Surface” Kihwan Kim, Peipei Xin, Jaeho Yun, William N. Shafarman

“Freeform Surface Relief Diffractive Optic for Photovoltaic Spectrum Splitting” Shelby D Vorndran, Silvana Ayala, Yuechen Wu, Juan M Russo, Melissa A Zaverton, Tom Milster, Raymond K Kostuk

“Optical Loss Analysis of Monolithic Perovskite/Si Tandem Solar Cell” Jonathan P Mailoa, Colin D Bailie, Austin J Akey, Eric T Hoke, Eric C Johlin, William H Nguyen, Sarah E Sofia, Michael D McGehee, Tonio Buonassisi

“Light Management in Mechanically-Stacked GaAs/Si Tandem Solar Cells: Optical Design of the Si Bottom Cell” Zhe Liu, Zekun Ren, Haohui Liu, Jonathan P. Mailoa, Nasim Sahraei, Sin-Cheng Siah, Sarah E. Sofia, Fen Lin, Tonio Buonassisi, Ian Marius Peters

“Numerical analysis of photon recycling and luminescent coupling in III-V/Si tandems” Zekun Ren, Jonathan Mailoa, Zhe Liu, Haohui Liu, SinCheng Siah, Tonio Buonassisi, Ian Marius Peters

“Process-to-Panel Modeling of a-Si/c-Si Heterojunction Solar Cells” Raghu Vamsi K. Chavali, Eric C. Johlin, Jeffery L. Gray, Tonio Buonassisi, Muhammad A. Alam

“Mechanically Stacked and Monolithically Integrated Perovskite/silicon Tandems and the Challenges for High Efficiency” Colin D. Bailie, Jonathan P. Mailoa, Eric C. Johlin, William H. Nguyen, Eric T. Hoke, Austin J. Akey, Tonio Buonassisi, Michael D. McGehee

“MgxCd1-xTe for II-VI/Si tandem solar cell applications” Shi Liu , Xin-Hao Zhao, Calli Campbell, Maxwell Lassise, Yuan Zhao, Ernesto Suarez, Yong-Hang Zhang

“Significantly improved interface recombination velocity and minority carrier lifetime for CdTe/MgCdTe double heterostructures” Shi Liu, Xin-Hao Zhao, Calli Campbell, Maxwell Lassise, Yuan Zhao, Yong-Hang Zhang

“Study of carrier lifetime degradation in (Zn)CdTe/MgCdTe double heterostructures” Xin-Hao Zhao, Shi Liu, Calli M Campbell, Yong-Hang Zhang

“Does Below-Bandgap Absorption Improve Solar Cell Efficiency?” Yuan Zhao, Yong-Hang Zhang

“Simulated Performance of Monocrystalline CdTe/MgCdTe Double Heterostructure Solar Cells” Yuan Zhao, Yong-Hang Zhang

“Monocrystalline ZnTe/CdTe/MgCdTe Double Heterostructure Solar Cells Grown on InSb Substrates” Ying-Shen Kuo, Jacob Becker, Shi Liu, Yuan Zhao, Xin-hao Zhao, Peng-Yu Su, Ishwara Bhat, Yong-Hang Zhang

“Effects of domain size in polycrystalline perovskite organic-inorganic hybrids investigated by spatially resolved optical spectroscopy” Henan Liu, Qiong Chen, Hui-Seon Kim, Nam-Gyu Park, Yong Zhang

RET Kyle Rawlings and Graduate Student Mentor Pradeep Balaji discussing printing quality.

Graduate Mentor Joe Karas explaining the process of IV Testing

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education & outreach

QESST hosts Research Experience Programs

This summer, QESST hosted its annual Research Experience for Undergraduates, Teachers and Young Scholars programs at Arizona State University, which has expanded significantly from previous years. Under the guidance of six student mentors, 24 participants are being provided with a hands-on experience manufacturing solar cells on a student-led pilot line. After completing “basic training” on how to make a solar cell, the students were split into teams to research a special topic. The participants came from a range of backgrounds and varied educational levels. Young Scholars from high schools got their first taste of what it is like to conduct research in the university cleanroom. Undergraduate students from both community colleges and universities will be able to present their research findings at the Silicon Workshop in Keystone, Colorado. STEM teachers are able to work over the summer on curriculum to take back to their classrooms. At the graduate level, students from QESST partner universities, the University of Delaware and Georgia Tech, had the opportunity to make a solar cell on a pilot production line and explore the issues and challenges involved in taking a new technology from a lab into commercial production. All students got to explore new concepts in solar cell design and fabrications. The program will conclude on August 7th, 2015. Students from all QESST universities will present their research at a luncheon and certificate celebration.

Summer program participants led by Professor Stuart Bowden, Lab Manager Bill Dauksher, and graduate student mentors

QESST Diversity Director, Professor Delia Saenz, discusses the promotion of inclusion in our society

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Summer Program Closing Session - August 7thAll QESST faculty, scholars, staff and industry members are invited to participate in the QESST Summer Program Closing Session on Friday, August 7, 2015, in the Engineering Research Center (1st floor). As in previous years, individuals participating in the summer programs - research programs for undergraduates, teachers, veterans, and young scholars - will have the opportunity to showcase their work in a poster session from 11:30 a.m. - 12:30 p.m. All are inivted to attend.

QESST participates in Engineering Adventure Camp

During the last two weeks of June, QESST partnered with the Fulton Schools of Engineering to present a solar energy component to the “Adventure Camps” at Arizona State University.

The program offered activities to engage students in science and engineering learning and technology development. Students built solar ovens, learned how a solar cell works, and used the engineering design process to build a mini solar powered theme park ride.

One of the weekly camps was geared exclusively towards girls entering grades 5-8. The purpose of this camp is to encourage young women to enter the field of engineering.

Young Scholars designing theme park rides.

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New QESST Student Leadership Council Officers

The QESST Scholars have elected the following individuals as officers of the Student Leadership Council for this upcoming academic year:

Genevieve HallPresident

Joe CarpenterOutreach

Sebastian HuseinIndustry/Innovation

Priyaranga KoswattaIndustry/Innovation

Tim ReblitzCommunications

First Solar Donation

One of QESST’s Industry Members, First Solar, generously is gifting 1000 Series 4™ PV Modules to QESST and ASU. First Solar’s Series 4™ and Series 4A™ PV Modules deliver superior performance and reliability, and have a proven energy yield advantage including:

- superior spectrum response resulting in a proven energy yield advantage in humid environments- independently certified for reliable performance in high temperature, high humidity, extreme desert and coastal environments- superior temperature coefficient resulting in greater energy yield in typical field operating conditions- anti-reflective coated glass that enhances energy production

ASU facilities is planning to install the modules on the new College Avenue Commons building (pictured below) which was used for the 2015 QESST Site Visit.

QESST Scholars in Industry Internships

QESST is fortunate to collaborate with its industry partners to provide internships for its students:

Mark Bailly, On Semiconductor

Matthew Erdman, Sandia National Labs

Abhishek Kumar, Applied Materials

Mehdi Leilaeioun, Solexel

Matthew Mehaffey, Sinton Instruments

Parth Mistry, Freescale

Tim Reblitz, Applied Materials

Dwarak Triplican, First Solar

Shelby Vorndran, Photon Engineering

Joshua Williams, Los Alamos National Labs

industrial engagement

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Photovoltaics Specialty Conference (PVSC)

Dozens of QESST faculty and Scholars participated in the 42th IEEE PVSC conference in New Orleans on June 14-19, 2015. During the conference, QESST hosted 30 Scholars and partner organizations for a networking lunch.

QESST member firms included: Applied Materials, AZUR Space, First Solar, Hanwha, Sinton Instruments, Yingli, Navy Research Labs and NREL. This is an annual event for QESST Scholars and industrial members.

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partner universities

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accepting the challengeElectricity is the lifeblood of modern society, powering everything from cities to pacemakers. With demand increasing, the electricity generating system faces challenges. These include harmful environmental impacts, threats to national security, resource supply problems, difficulties in powering autonomous applications, and over a quarter of the world’s population without access to electricity. These all indicate the need for a new electricity generation system. QEEST addresses these challenges by supporting a system of photovoltaic science and innovation—a system that breaks away from the waste and inefficiencies of unsustainable fossil fuels and generates power using our favorite sustainable and unlimited resource: the Sun.

qesst.asu.edu

QESST is an NSF/DOE Engineering Research Center funded in 2011 under cooperative agreement EEC-1041895 and headquarted at Arizona State University