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Alumni Profiles

QESST Scholar Alumni

Austin Akey



Massachusetts Institute of Technology
Post-Doc
akey@mit.edu

Advisor: Dr. Tonio Buonassisi

Michael Bernstein



Arizona State University
Ph.D. Student
mab09r@gmail.com

Advisor: Dr. Zach Holman

Mathieu Boccard



Arizona State University
Post-Doc
mathieu.boccard@alumni.epfl.ch

Advisor: Dr. Zak Holman

Lei Chen



University of Delaware
Ph.D. Student
graffaner@gmail.com
Lchenud@udel.edu

Physics
Advisor: Dr. William Shafarman
Phone: (302) 831-2326
Thesis project:
» Development and characterization of (Ag,Cu)(In,Ga)Se2 thin films deposited by three-stage co-evaporation
Expertise:
» Device fabrication and optimization of wide band gap thin-film solar cells with co-evaporated (Ag,Cu)(In,Ga)Se2 absorbers
» multi-source physical vacuum co-evaporation system

Other projects:
Material analysis of co-evaporated (Ag,Cu)(In,Ga)Se2 film in SEM, EDXS, XRF, XRD, XPS, TEM etc.; device characterization of (Ag,Cu)(In,Ga)Se2 solar cells through measurements of JV, CV, QE etc.
Journal papers/conferences etc.
» Brent Shu, Ujjwal Das, Lei Chen, Lulu Zhang, Steven Hegedus, and Robert Birkmire, Design of Anti-Reflection Coating for Surface Textured Interdigitated Back Contact Silicon Hetero-junction Solar Cell, 2012 38th IEEE Photovoltaic Specialists Conference

 

Angelo Delluomo



Arizona State University
Undergraduate
Angelo.Delluomo@asu.edu

Advisor: Dr. Zak Holman

Laura Ding



Arizona State University
Post-Doc
laura.ding@asu.edu

Advisor: Dr. Mariana Bertoni

Cris Flowers



California Institute of Technology
Ph.D. Student
Cristofer.flowers@gmail.com

Chemical Engineering
Advisor: Dr. Harry Atwater
Thesis project and Research Interests:
Full Spectrum Ultrahigh Efficiency Spectrum Splitting Photovoltaics
Expertise:
EQE, J-V, III-V electrical modeling, contact optimization, module electrical design
Other projects / Collaborations:
Integrated maximum power point tracker and DC-DC converter for independent electrical connection of subcells, with Sayfe Kiaei and Bertan Bakkaloglu

Christina Foster



Arizona State University
Ph.D. Student
Christina.Hobson@asu.edu

School of Engineering Education
Advisor: Dr. Dale Baker

I am a Ph.D. student in Engineering Education dedicated to improving the status of engineering education in K-12. My research focus is on identifying ways to motivate K-12 students to learn engineering and on ways to develop systems thinking, a necessary habit of mind for engineers of the 21st century. My research efforts began during my first year of graduate school as an NSF GK-12 fellow where I designed and implemented five weeks of project-based lessons based on the NAE’s Grand Challenges for Engineering for sixth graders. I continued my research efforts by working on a large-scale engineering education project, Girls in Engineering, as well as several small-scale projects focused on teacher preparedness and efficacy in teaching engineering under the direction of Dr. Tirupalavanam Ganesh. Currently in my third year of studies, I am focused on the QESST educational research program with the goal of evaluating and developing resources for photovoltaics (PV) instruction under the direction of Dr. Jenefer Husman. I am also currently piloting my dissertation project, titled Designing a Bioengineering Learning Experience to Develop Systems Thinking in Middle School Grades.
Journal papers/conferences etc.
Christina has presented the progress of her doctoral work at the NSF GK-12 Rocky Mountain Regional Conference in Denver, Colorado and at the Grand Challenge K-12 Partners Program Regional Conference in Tempe, AZ. Her work will also be presented at the Frontiers in Education Conference in Seattle, Washington this fall.

 

Hai Huang



Arizona State University
Ph.D. Student
hhuang60@asu.edu

Advisor: Dr. Hongyu Yu
Phone: (480) 370-8259
Thesis project:
Development of micro seismometer based on Micro-Electro-Mechanical Systems (MEMS) and Molecular Electronics Transducers (MET) for planetary exploration
Expertise:
FLUENT CFD simulation, Microfabrication for semiconductor and MEMS devices.

Other projects:
Flexible MEMS antenna
Journal papers/conferences etc.
» Xiaotun Qiu, Rui Tang, Ranran Liu, Hai Huang, Shengmin Guo, Hongyu, Yu “A micro initiator realized by reactive Ni/Al nanolaminates”, Journal of Materials Science: Materials in Electronics, 2012.
» Lei Sun, Guoxuan Qin, Hai Huang, Han Zhou, Nader Behdad, Weidong Zhou, and Zhenqiang Ma “Flexible high-frequency microwave inductors and capacitors integrated on a polyethylene terephthalate substrate”, Appl. Phys. Lett. 96, 013509 (2010).
» J. Oiler, X. Qiu, J. Zhu, R. Tang, S.J. Chen, H. Huang, K. Holbert, H. Barnaby, and H. Yu, “The sensitivity enhancement for the radiation sensor based on film bulk acoustic-wave resonator”, Transducers’11, the 16th International Conference on Solid-State Sensors, Actuators and Micro Systems. June 5-9, 2011, Beijing, China.
» R. Tang, X. Qiu, J. Zhu, J. Oiler, H. Huang, H. Wang and H. Yu, “pH measurements with ZnO based surface acoustic wave resonator”, Transducers’11, the 16th International Conference on Solid-State Sensors, Actuators and Micro Systems, June 5-9, 2011,Beijing, China.
» H. Huang, Z. Ma, “Influence of Substrate Parasitic Effects on Power Gain Relation between CE and CB SiGe HBTs”. IEEE 8th Topical Meeting on Silicon Monolithic Integrated Circuits in RF Systems (SiRF 2008), Jan.23-25, 2008, Orlando,FL.

 

Chikara Kakizawa



Arizona State University
Chikara.Kakizawa@asu.edu

School of Electrical, Computer, and Energy Engineering

Yeongho Kim

Yeongho Kim

Arizona State University
Ph.D. Student
ykim172@asu.edu

School of Electrical, Computer, and Energy Engineering
Advisor: Dr. Christiana Honsberg
Phone: (420) 241-0666
Expertise:
» 1. III-V semiconductor material growth using Riber and Veeco MBE system
» 2. Semiconductor device fabrication
• Photolithography: Quantum Cascade Lasers/Solar Cells
• Film & Metal Deposition: PECVD/E-beam and Thermal Evaporation
• Etch: RIE/wet etch
• Annealing: RTA/IR Furnace
• Wire bonding/Wafer polishing
» 3. Material and device characterization
• Deep Level Transient Spectroscopy (DLTS)/Hall Effect Measurement
• FTIR Spectroscopy/High Resolution X-ray Diffraction (HR-XRD)/Photoluminescence (PL)/ Photoreflectance (PR)
• Field Emission Scanning Electron Microscope (FE-SEM)/Atomic Force Microscope (AFM)
• Device Measurements : Solar cells/Avalanche photodiodes (APDs)/Mach–Zehnder Interferometer (MZI) electro-optical modulators

James LeBeau



Arizona State University
Ph.D. Student
James.LeBeau@asu.edu

School of Electrical, Computer, and Energy Engineering
Advisors: Dr. Stuart Bowden
Phone: (602) 427-7163
Thesis project:
Laser Wafering. A novel sub band gap laser process for layer liftoff of semiconductors.
Expertise:
» Four-point-probe
» Laser micro-machining
» VCSEL Photoluminescence

Other projects:
Diffusion furnace characterization, stress/strain of quantum pyramidal dots, single cell solar module design and construction.
Journal papers/conferences etc.
» PVSC 2012 “Laser Wafering”

 

Junli Li



University of Delaware
Ph.D. Student
junlili@udel.edu

Advisor: Dr. Lado Kurdgelashvili

Shi Liu



Arizona State University
Ph.D. Student
Shi.Liu@asu.edu

School of Electrical, Computer, and Energy Engineering
Advisor: Dr. Yong-Hang Zhang
Thesis project:
» Design, growth and testing of photovoltaic devices
Expertise:
» Device modeling (Matlab, Silvaco, PC1D)
» MBE growth
» Material and device characterization (Photoluminescense, Hall, Atomic Force Microscopy, I-V, External quantum efficiency)

Steven Limpert

Steven Limpert

Arizona State University
Ph.D. Student
Steven.Limpert@gmail.com

School of Electrical, Computer, and Energy Engineering
Advisor: Dr. Stephen Goodnick
Phone: (484) 886-9680
SteveLimpert.blogspot.com/
Thesis project: Hot Carrier Solar Cells
Other related projects: Silicon Solar Cell Modeling and Manufacturing, Global PV Policy

I began working in photovoltaics in 2010 during the summer following my sophomore year as part of a National Science Foundation (NSF) Research Experience for Undergraduates (REU) program at Arizona State University. As part of that program, I wrote a 1D drift diffusion model of monocrystalline silicon solar cells in MATLAB and simulated monocrystalline silicon solar cells in Synopsys’ Sentaurus TCAD in order to look at the performance effects of surface recombination at the edges of solar cells. In the fall of 2010, I was awarded a grant from the Circumnavigators Club Foundation to circumnavigate the globe while performing a research project of my own design. As a foundation scholar, during the summer of 2011, I traveled by myself to Spain, Germany, Qatar, India, Bangladesh, Japan and Australia in order to interview academic researchers, business people and policy experts working in the area of photovoltaics. Upon my return to the US, I spent my senior year manufacturing silicon solar cells as a member of the QESST Thrust 1 Student Pilot Line as part of my senior design project. In the spring of 2012, I completed my undergraduate degree in electrical engineering. I look forward to working towards my graduate degree as a member of QESST and pursuing research at the University of New South Wales starting in January of 2013 as a US Fulbright Climate Change and Clean Energy Scholar. In my free time, I enjoy performing on the trumpet.
Journal papers/conferences etc.
» S. Limpert and H. Battelle, “An Overview of the Bangladeshi
Photovoltaic Market, Related Policies and Deployment Challenges”
Conference Record, 38th IEEE Photovoltaic Specialists Conference,
Austin, June 2012.
» S. Limpert, “Solar Energy Technologies: a Comparative Study of
Commercial Applications and Government Policies” Conference
Record, 1st Arizona State University and University of Arizona Student
Renewable Energy Science Conference, Tempe, April 2012.

 

Robert Lovelett



University of Delaware
Ph.D. Student
Lovelett@udel.edu

ChemE
Advisors: Babatunde A. Ogunnaike, Robert W. Birkmire
Thesis project and Research Interests:
Production of CIGS via precursor reaction
Expertise:
Reaction kinetics, control systems, design of experiments, statistics, mathematical modeling
Other projects / Collaborations:
In-situ characterization of CIGS via synchrotron x-ray methods with Prof. Bertoni at ASU
Phone: (302) 831-2326

Robert is a graduate student at the University of Delaware who is working on a joint project in the Department of Chemical and Biomolecular Engineering and the Institute of Energy Conversion. His research involves the process engineering of CIGS solar cell fabrication to improve efficiency and increase process throughput. He uses computer modeling to screen and investigate potential reactor designs. His experimental methods are used to validate and refine the models and to characterize CIGS morphology and device performance.

 

Edgar Martí-Arbona



Arizona State University
Ph.D. Student
Edgar.Marti-Arbona@asu.edu

School of Electrical, Computer, and Energy Engineering
Advisor: Dr. Safye Kiaei

Edgar is a PhD student under the supervision of Dr. Kiaei at Arizona State University (ASU), Tempe campus. He completed his Master and Bachelor degrees at the University of Puerto Rico at Mayaguez. He is currently working on a project focused in improve the power management of photovoltaic systems. In this project, he is using his analog circuit and system design skills to propose innovative power management architecture. Before this project, he was working in the design of a high efficiency optical feedback LED driver at ASU.

 

Neel Mistry



Arizona State University
Ph.D. Student
nmistry1@asu.edu

Advisor: Dr. Bakkaloglu

Sharlissa Moore



Arizona State University
Ph.D. Student
Sharlissa.Moore@asu.edu

Advisor: Dr. Ed Hackett
Phone: (605) 484-5450
Thesis project:
The Desertec Industrial Initiative (Dii) is a unique German corporation with 56 shareholder and partner companies, which envisions building 40 large-scale solar and wind power plants in North Africa that will be connected to an integrated transmission network in the Mediterranean region to provide sustainable and affordable electricity for Europe and North Africa. Desertec is immense in scale and ambition, demanding attention both in its own right and as a model for similar enterprises in other regions. My dissertation will examine the co-shaping of the Desertec network and vision. My objectives are analytic and normative: 1) to understand how a network of actors construct and negotiate a vision for a regional energy system and 2) to evaluate the justice implications of energy systems, using a framework grounded in the literature and refined by this empirical study.
Expertise:
Energy Policy and Governance, social dimensions of solar power, social aspects of large-scale deployment of PV and CSP

Other projects:
» Study of controversies over solar power plant siting in California
Journal papers/conferences etc.
» Moore, S. Envisioning the Social and Political Dynamics of Energy Transitions: Sustainable Energy for the Mediterranean Region. Science as Culture, 22(2), 181-188.
» Moore, S. 2012. Book review of Renewable Energy and the Public. By Patrick Devine-Wright. Research Policy Review.
» Aragon, N. et al. 2011. Miller, C. & S. Moore. (eds.) Arizona’s Energy Future. Background Report Prepared for Arizona Town Hall.
» Miller, C. & S. Moore. 2011. Introduction. In Arizona’s Energy Future. Background Report Prepared for Arizona Town Hall.
» Moore, S. & R. Shangraw. 2011. Managing Risk and Uncertainty in Large-Scale University Research Projects. Research Management Review. 18(2).

 

Katie Nelson



Arizona State University
Ph.D. Student
kmuto@asu.edu

Advisor: Dr. Jenefer Husman
Phone: (480) 768-7238 Katie is looking at how students learn PV engineering. Primarily, she is focusing on how students go through the process of conceptual change when learning about semiconductors – with an emphasis on semiconductor content that has to do with complexity. She is also teaching freshman engineering design.

Katie is featured in this article in ASEE PRISM Summer 2013

Krista Puruhito



Arizona State University
Ph.D. Student
krista.puruhito@asu.edu

Advisor: Dr. Jenefer Husman
Phone: (480) 861-0032
Thesis project:
Puruhito, K. Husman, J. Ganesh, T. & Stump, G. (Oct, 2011). Increasing Instrumentality Without Decreasing Instructional Time: An Intervention for Engineering Students. Proceedings of the Frontiers In Education Conference; Rapid City, SD.
Expertise:
Perceptions of instrumentality

Krista completed her undergraduate degree at Northern Arizona University and her Master’s degree (educational psychology) at Arizona State University. She is currently a doctoral student at Arizona State University in the Family and Human Development Program. Krista works with Dr. Jenefer Husman on various projects that look at motivation in the educational context.
Journal papers/conferences etc.
» Puruhito, K. Husman, J. Ganesh, T. & Stump, G. (Oct, 2011). Increasing Instrumentality Without Decreasing Instructional Time: An Intervention for Engineering Students. Proceedings of the Frontiers In Education Conference; Rapid City, SD.» Husman, J., Puruhito, K., Ganesh, T., Stump, G., & Brem, S.K., (2010). Increasing Motivation without Decreasing Instructional Time: A Brief Intervention to Improve Engineering Students’ Task value. Paper presented at the 2010 bi-annual meeting of the International Conference on Motivation, Porto, Portugal.

 

Tim Reblitz

Tim Reblitz

Arizona State University
Ph.D. Student
treblitz@asu.edu

School of Electrical, Computer, and Energy Engineering
Advisor: Dr. Stuart Bowden
Phone: (480) 789-9870
LinkedIn.com/in/TimReblitz
Expertise:
» Silicon photovoltaic cell fabrication and characterization.
» n-Type mono-Si PV cells with p+ emitters diffused from PECVD a-Si.
» Application Engineering (PHP, SQL, MATLAB, LabVIEW)

Other projects:
» Conception and Development of PV applications eTraveller and Minotaur. eTraveller is a web-based application used for organization and analysis of data related to the production and characterization of photovoltaic devices.
» Prototyping of PV modules
Journal papers/conferences etc.
» Reblitz, T., Bowden, S., Herasimenka, S. (Jul, 2013). p+ Emitters on n-Type c-Si using Rapid Thermal Annealing of PECVD a-Si films and Aluminum Metallization . Proceedings of the 39th IEEE PVSC; Tampa, FL.

» Reblitz, T., Tracy, C., Herasimenka, S., Dauksher, W., Bowden, S., (Jul, 2012). Web Applications for: Centralization of Photovoltaic Cell Production and Characterization Data, and Processing of Sentaurus Simulation Files. Proceedings of the 22nd Workshop on Crystalline Silicon Solar Cells & Modules: Materials and Processes; Vail, CO.

 

Ben Wender



Arizona State University
Ph.D. Student
bwender@asu.edu

School of Sustainable Engineering and the Built Environment
Advisor: Dr. Thomas P. Seager
Phone: (505) 660-6782

My research is directed towards environmental assessment of novel renewable energy technologies. While emerging technologies hold promise for improvements in energy and material utilization efficiency, it is important to evaluate these technologies from a life cycle perspective such that we don’t cause more damage to the environment in the name of saving it. I am developing new methods of life cycle assessment (LCA), applicable to energy technologies before they are implemented at scale, based on thermodynamic modeling of manufacturing processes and use-phase performance. Other research includes the use of Value of Information analysis to prioritize nanomaterial EH&S research, and broader social, ethical, and legal implications of emerging technologies.
Journal papers/conferences etc.
» Wender, B.A., and Seager, T.P. 2011. “Towards prospective life cycle assessment: Single wall carbon nanotubes for lithium-ion batteries”. IEEE, Proceedings International Symposium on Sustainable Systems and Technology, Chicago, 2011.
» Wender, B.A., and Seager, T.P. (Under Review). “Anticipatory Life Cycle Assessment of SWCNT-enabled Lithium ion Batteries”, in Rickerby, D., Sustainable Nanotechnology Manufacturing, Martle BV, Lieden, NL.
» Wender, B.A., Foley, R., Guston, D.H., and Seager, T.P. (Under Review). “Anticipatory Governance and Anticipatory Life Cycle Assessment”. Journal of Nano Law and Business.

 

Patricia Yen



Massachusetts Institute of Technology
Ph.D. Student
paxty@mit.edu

Advisor: Dr. Tonio Buonassisi

Carissa Eisler



Caltech
Ph.D. Candidate
ceisler@caltech.edu
Personal Profile Page

Advisor: Dr. Harry Atwater
Phone: (626) 395-2380
Thesis project: Eisler is working towards creating ultrahigh efficiencies in solar cells through sidewall passivation of III-V semiconductors and unconventional optical architectures for multijunction cells. She is studying various chalcogenide-based chemical treatments for exposed sidewalls in III-V semiconductors to boost performance and durability in small (= 1 mm2) cells. She is quantifying the passivation through a number of different techniques, such as light beam induced current maps to extract the surface recombination velocity and measuring the current-voltage characteristics in a solar simulator to determine efficiency enhancements. Additionally, she is also working on unconventional multijunction architectures, such as methods for spectral splitting, to approach solar conversion efficiencies of over 50%.
Expertise:
Photoluminescence, light beam induced current measurements, solar cell characterization with a solar simulator, and simulation of solar cells using AFORS-Het (device physics equation solver for modeling of realistic solar cell performance, limited to single junctions).

Journal papers/conferences etc.
» Eisler, C., Sheldon, M., Atwater, H. “Enhanced Performance of Small GaAs Solar Cells via Edge and Surface Passivation with Trioctylphosphine Sulfide.” PVSC. Austin, Texas. March 2012. Poster.» Eisler, C., Sheldon, M., Kayes, B., Atwater, A. “Enhanced Performance of III-V Compound Solar Cells via Edge and Surface Passivation with Trioctylphosphine Sulfide and Related Surfactants.” Spring MRS. San Francisco, CA. February 2012. Lecture.» Sheldon, M. T., Eisler, C. N. and Atwater, H. A. (2012), GaAs Passivation with Trioctylphosphine Sulfide for Enhanced Solar Cell Efficiency and Durability. Adv. Energy Mater., 2: 339–344. doi: 10.1002/aenm.201100666.» Sheldon, M., Eisler, C., Atwater, A. “Towards `Self-Healing’ Solar Cells: Dynamic GaAs Passivation Using Sulfur-Functionalized Surfactants.” Fall MRS. Boston, MA. November 30, 2011. Lecture.

 

David P. Fenning



MIT
Masters Student
dfenning@mit.edu

Advisor: Tonio Buonassisi
Thesis project:
David studies the control of performance-limiting metal impurities during silicon solar cell processing. As part of this effort, he measures the effect of processing on the distributions of metal nanoprecipitates in industrially relevant materials using synchrotron-based X-ray fluorescence and absorption spectroscopy. He combines this experimental work with simulations of phosphorus diffusion gettering in order to develop and evaluate new, material-specific processing regimes to improve cell performance.
Expertise:
X-ray fluorescence, absorption spectroscopy, phosphorus diffusion modeling, standard solar cell characterization techniques

Other projects:
» Fundamental metal-silicon thermodynamics and kinetics, interactions between metal impurities and structural defects, applications of metal impurity retrograde melting in silicon to microwire growth
Journal papers/conferences etc.
» “Iron Distribution in Silicon After Solar Cell Processing: Synchrotron Analysis and Predictive Modeling”
D. P. Fenning, J. Hofstetter, M. I. Bertoni, S. Hudelson, M. Rinio, J. F. Lelièvre, B. Lai., C. del Cañizo, and T. Buonassisi; Applied Physics Letters 98, 162103 (2011)» “Impurity-to-Efficiency Simulator: Predictive Simulation of Silicon Solar Cell Performance Based on Iron Content and Distribution”
J. Hofstetter, D. P. Fenning, M. I. Bertoni, J. F. Lelièvre, C. del Cañizo, and T. Buonassisi; Progress in Photovoltaics: Research Applications, 19, 4, pp. 487-497 (2011)» “Nanoprobe X-ray Fluorescence Characterization of Defects in Large-Area Solar Cells”
M. I. Bertoni, D. P. Fenning, M. Rinio, V. Rose, M. Holt, J. Maser, and T. Buonassisi; Energy Environ. Sci., 4, pp. 4252-4257 (2011)

 

Somayeh Imani



University of New Mexico
Ph.D. Student
imani@ece.unm.edu

Advisor: Dr. Olga Lavrova
(505) 620-7084

Jonathan Pradana Mailoa



MIT
Ph.D. Student
jpmailoa@mit.edu

Advisor: Tonio Buonassisi
Phone: (617) 763-1602
Thesis project:
My main thesis project is on proving the concept of intermediate band solar cell using impurity band. The impurity band is achieved by doping the light absorbing material beyond its equilibrium solubility limit. The goal of the project is to show that two-photon absorption is possible with the aid of impurity band as the intermediate state, allowing us to extract carrier from the solar cell using below bandgap photons.
Expertise:
» UV-VIS spectrophotometry for material’s light absorption characterization.
» Finite Difference Time Domain (FDTD) simulation -> optical simulation that is particularly useful for sub-wavelength structure.
» Colloidal lithography for nano-patterning using Langmuir-Blodgett method.

Other projects:
» I do study of light propagation in sub-wavelength nanostructure for solar cell application using finite element simulation. The focus so far has been on system/structure that can actually be fabricated. I have previously done some experiments on nanotexture fabrication based on my simulation result as well.
Journal papers/conferences etc.
» O Uzuner, J Mailoa, R Ryan, T Sibanda, “Semantic relations for problem-oriented medical records”, Artificial Intelligence in Medicine 50, 2 (2010)

 

Akhil Mehrotra



University of Houston
Ph.D. Student
makhil85@gmail.com

Advisor: Dr. Alex Freundlich
Phone: (713) 628-9691
Expertise:
Simulation modeling/ characterization techniques etc.

I am Akhil Mehrotra, a 4th year PhD graduate student in Electrical and Computer engineering department. My research topic is “Defect and radiation tolerant III-V solar cells”. My research objective is to model and fabricate III-V solar cells using MBE with optimal device designs so that they show defect and radiation tolerant behavior. Combining the existing drift-diffusion model for the solar cells with defect/ radiation degradation model one can find an innovative way of improving the efficiency of the solar cells by thickness-doping optimization.
I have also been involved in development of III-V photovoltaics on inexpensive metallic flexible substrates. It has been shown that growth of single crystalline GaAs on poly-crystalline flexible substrates (Hastealloy Ni-Cr-Mo alloy) is possible using oxide ceramic buffer layers followed by thin deposition of epitaxial Ge layer using IBAD. GaAs can be grown epitaxially using MBE but major drawback is the presence of high dislocation densities (5x108cm-2).
I have been involved in modeling of multijunction solar cells, fabrication of solar cells using MBE, processing of the solar cells, characterization using HRXRD, ECV, PL, PR, FTIR and SEM.
Journal papers/conferences etc.
» Akhil Mehrotra, Andenet Alemu and Alex Freundlich
“Modeling of defect-tolerant thin multijunction solar cells for space application”
Conference on Physics, Simulation and Photonic Engineering of Photovoltaic Devices, Proc. SPIE,
Vol. 8256, pg. 82561H, 2012
» Wei Wang, Akhil Mehrotra, Andenet Alemu and Alex Freundlich
“Minimizing solar cell reflection loss through surface texturing and implementation of 1D and 2D subwavelength dielectric gratings”
Conference on Physics, Simulation and Photonic Engineering of Photovoltaic Devices, Proc. SPIE,
Vol. 8256, pg. 82561A, 2012
» Akhil Mehrotra, and Alex Freundlich
“Superior Radiation and Dislocation Tolerance of IMM Space Solar Cells”
Proc. 38th IEEE Photovoltaics Specialist Conference, 924, 2012
» Akhil Mehrotra, Alex Freundlich, Venkat Selvamanickam, Renjie Wang, and Senthil Sambandam
“Epitaxial Growth of (100) GaAs on CeOx-Coated Flexible Metal Substrates”
Proc. 38th IEEE Photovoltaics Specialist Conference, 755, 2012“Drift-Diffusion modeling and optimal designs for dislocation and radiation tolerant GaAs solar cells” (in progress JAP)

 

Ashley Morishige



MIT
Ph.D. Student
aemorish@mit.edu

Advisor: Tonio Buonassisi
Dissertation topic:
Predictive Engineering of Metal Impurities in n-type Crystalline Silicon for Cost-Effective, High-Performance Solar Cells
Expertise:
» Synchrotron-based micro-X-Ray Fluorescence Spectroscopy (XRF)
» Simulation modeling/ characterization techniques etc.
» Simulation – Matlab, Sentaurus
» Experimental tools – 4 pt. probe, POCl3 diffusion furnace, wet bench processing for silicon

Other projects:
» Simulation with Impurity-to-Efficiency tool and experiments comparing effect of alternative high-temperature POCl3 diffusion on gettering efficiency and minority carrier lifetime;
» Modeling point and extended defects in silicon in Sentaurus
Journal papers/conferences etc.
» Poster: Co-optimizing the phosphorus diffusion time-temperature profile for gettering and throughput, 5th International Workshop on Crystalline Silicon Solar Cells, 2 Nov 2011.
» Poster and Conference Proceeding: Simulated Co-Optimization of Crystalline Silicon Solar Cell Throughput and Efficiency Using Continuously Ramping Phosphorus Diffusion Profiles, 38th IEEE-PVSC, 2 June 2012.

 

Nassim Rahimi



University of New Mexico
Ph.D. Student
nrahimi@unm.edu

Advisor: Dr. Luke Lester
Thesis project:
Design and Characterization of Digital-Alloy Thermo-Photovoltaics
Expertise:
» Characterization techniques: SEM, Nomarski Microscopy, Four Point Probe Resistivity (4PP), IV Measurement, Variable Angle Spectroscopic Ellipsometry (VASE), Surface PhotoVoltage (SPV), Transmission/ Reflection Measurement, TEM (in progress), Xray-Diffraction (in progress), Photoluminescence Measurement (PL), Hall Measurement, Wire Bonding
» Processing Techniques: Lithography, Metal Deposition Techniques, Wet and Dry Etching (ICP and Chemicals), Anti Reflection Coating Deposition (PECVD)
» Programming: C programming, MATLAB, Computational Methods in Physics, Molecular Dynamics Simulations, AutoCad, LabView (in progress)

Nassim Rahimi graduated from Iran University of Science and Technology in 2005 with a B.S degree in Atomic and Molecular Physics. In 2009, she received her M.Sc. degree in Photonics from the Laser and Plasma Institute of Shahid Beheshti University (Formerly, National University of Iran). She is currently pursuing her Ph.D. in Optical Sciences and Engineering at the Center for High Technology Materials. She is also socially active and involved in some extracurricular activities such as rock climbing, hiking, yoga, painting and reading classical novels and poems.
Journal papers/conferences etc.
» Rahimi. N, Kharrazi. Sh, Shokri. B., “Investigation of Shape Evolutions of Silver Nanoparticles” Oral presentation at the 15th Iranian Conference on Optics and Photonics, Isfahan, January,Iran, 2009» Rahimi. N, Kharrazi. Sh, Shokri. B., “Investigations on the Effect of Surfactants on the Shape of Metallic Nanoparticles”Oral presentation at the 9th Conference on Condensed Matter, Ahvaz, February, Iran,2009» Rahimi. N, Kharrazi. Sh, Shokri. B., “The Effect of Shape on the Optical Properties of Silver Nanoparticles” Oral presentation at the Nanotech Insight Conference 2009, Barcelona, March-April, Spain, 2009» F. Grillot, N. A. Naderi, J. Wright, N. Rahimi, R. Raghunathan, M. Crowley and L. F. Lester, Dual-Mode Quantum Dot Laser Operating in the Excited State, (Oral Presentation), The 24th Photonics Society Meeting, Arlington, 9-13 October, USA, 2011

 

Orlando Romero



University of New Mexico
Ph.D. Candidate
oromero@unm.edu

Advisor: Dr. Luke F. Lester
Phone: (505) 903-2193

Orlando Romero received his BSEE and MSEE from the University of New Mexico in 2009 and 2011 respectively. His undergraduate concentration was in applied electromagnetics, and master’s project focused on power systems for micro autonomous vehicles. For his PhD, Orlando is investigating molecular beam epitaxy growth techniques and characterization of III-V solar cells, and in particular, multi-junction low bandgap, thermo-photovoltaic cells. He is proficient in the following characterization methods: x-ray diffraction, Nomarski microscopy, photoluminescent characterization, atomic force microscopy, Hall effect measurements.

 

Yeng–Chieh Tsai



University of Delaware
Ph.D. Student
udjaytsai@gmail.com

Advisor: Dr. Lado Kurdgelashvili
Phone: (302) 250-0349Tsai is a foreign phD student from Taiwan. In 2009, Yeng-Chieh Tsai received the Master degree in Environmental Engineering in University of Delaware. His research topic was the water quality monitoring with DNA-microarrays. From 2009 to 2011, Tsai worked in Batta Environmental Laboratory as an environmental analyst, analyzing the asbestos –contained materials and soil samples in the environment. Tsai also got his certificate of Engineer in Training of State Maryland during this period. The long term nuclear power controversy and related energy issues in Taiwan inspired Tsai to start the phD study in CEEP from Sep, 2011.

Gopi Krishna Vijaya



University of Houston
Ph.D. Student
vgopik@gmail.com

Advisor: Dr. Alex Freundlich
Phone: (713) 614-6674
Thesis project:
Working on the III-V Dilute Nitride multi quantum well solar cells, with growth being done on MBE and characterization done using PR, PL, TEM, and IV measurements, among others. On the theoretical front, development of a model to predict the efficiencies of the cells.
Expertise:
» Simulation, mainly done on Matlab.
» Characterization: PR, PL, TEM, IV, C-V Profiling

Other projects:
Undergraduate mentoring, of a student who is in QESST (Camden Kirkland)
Journal papers/conferences etc.
» “Effect of rapid thermal annealing on optical and photovoltaic properties of dilute nitride bulk and quantum well materials.”M C Wu, A Mehrotra, G K Vijaya, A Alemu, A Freundlich, Proc of SPIE Photonics West 7933-86, (2011) (Poster)
» “Dilute nitride multi-quantum well multi-junction design: a route to ultra-efficient photovoltaic devices” GK Vijaya, A Alemu, A Freundlich, Proc of SPIE Photonics West, 7933-15, (2011).
» “Modeling of 1eV dilute nitride multi quantum well solar cells”, GK Vijaya, A Alemu, A Freundlich, Proc of 35th IEEE PVSC, p 380-384, (2010)

 

Shelby Vorndran



University of Arizona
College of Optical Science
Ph.D. Student
svorndran@optics.arizona.edu

Advisor: Dr. Raymond Kostuk
Research Focus:
» Designing and fabricating Holographic Optical Elements to manage light in photovoltaic devices.

Expertise:
» Holographic and Diffractive optical theory, modeling holograms (using RSoft, Zemax, and Matlab), design and fabrication of holograms (laser operation, alignment of optical components, mixing and coating dichromated gelatin film, dark room development, characterization).
Current Projects:
» A “Radiometric Ratio” characterization method to find the ideal concentration level for CPV installations in site-specific irradiance conditions.
» Designing holographic spectrum-splitting devices for hybrid thermal/PV, thermal/biofuel, thermal/daylighting applications.
» Designing a holographic spectrum-splitting device for hybrid PV/photosynthesis greenhouses.
Teaching Experience:
» Completing the Certificate in College Teaching program, which includes coursework, one academic year of supervised college teaching, and a teaching portfolio.
» TA for Photovoltaic Solar Energy Systems, ECE/OPTI 414/514.
» Volunteer at Hollinger Elementary School in Tucson, Arizona: teaching science topics and assisting with a class science fair project.

Kenneth Zame



University of Delaware
Ph.D. Student
kkzame@udel.edu

Advisors: Dr. Young-Doo Wang & Dr. John Byrne
Phone: (302) 831-8405Kenneth Zame has a Bachelor of Science degree in Chemical Engineering and a Masters degree in Environmental Studies. He is currently a PhD Candidate in Energy and Environmental Policy at University of Delaware. His research interest is in energy, water and climate change policy. Kenneth contributed to a project which improves integration of storage modeling in PV Planner®; a software which analyzes the benefits of PV technology, storage and policy.

Journal papers/conferences etc.
» “Improvements in Regional Equity through the Reduction in Water Debt,” Young-Doo Wang, Sung Goo Kang, Kenneth Zame, 11th Hawaii International Conference on Social Sciences, Honolulu Hawaii, May, 2012.» “Carbon dioxide Capture from a Point Source Using Chlorella vulgaris,” Kenneth Zame, Douglas Price, 95th Ecological Society of America Annual Meeting, Pittsburg Pennsylvania, August, 2010.

 

Derek Caselli, Ph.D.



Arizona State University
Derek.Caselli@asu.edu

Nanophotonics
Advisor: Dr. Cun-Zheng Ning
Phone: (480) 330-4636

My research focuses on the design, simulation, and fabrication of solar cells for a spectrum-splitting photovoltaic system using spatially composition-graded semiconductor alloys. By creating a gradient in the local temperatures and source vapor compositions over the length of the substrate during a chemical vapor deposition process, semiconductor alloys can be grown with compositions and bandgaps varying continuously across a wide range on a single substrate with a single, inexpensive growth. These can be used as the absorbing materials in a set of solar cells for a high efficiency spectrum-splitting photovoltaic system, where the single growth has the potential to unify the typically disparate fabrication processes of the various cells, simplifying the manufacturing process and cutting costs.
Journal papers/conferences etc.
» D.A. Caselli and C.Z. Ning, “High-performance laterally-arranged multiple bandgap solar cells using spatially composition-graded CdxPb1-xS nanowires on a single substrate: a design study,” Optics Express 19 (S4), A686-A694 (2011).
» D. Caselli and C.Z. Ning, “Full-Spectrum Laterally-Arranged Multiple-Bandgap InGaN Solar Cells,” to be published in the Proceedings of the 38th IEEE PVSC (2012).

 

Matthias Karow



Arizona State University
Fulbright Visiting Scholar
mkarow@asu.edu

School of Electrical, Computer, and Energy Engineering
Advisor: Dr. Christiana Honsberg
LinkedIn.com/in/MatthiasKarow
Expertise:
MBE growth, HR-XRD characterization, Hall-effect measurements


During his one year at Arizona State University as a Fulbright Scholar from Goettingen University, Germany, Matthias is affiliated with the MBE group of the Solar Power Laboratory. Epitaxial growth of III-As compounds with a Veeco setup is thereby the origin for further semiconductor characterization. High Resolution X-Ray Diffraction (HR-XRD) is a primary means in order to investigate materials not only suitable for Solar Cells application, but also regarding fundamental defect creation mechanisms.

Reid Juday, Ph.D.



Arizona State University
reid.juday@asu.edu

Advisor: Dr. Fernando Ponce
Phone: (480) 727-8297

The main focus of my research is on the luminescence of wide band gap semiconductors. I am very interested in the luminescence and conductivity of p-type GaN and p-type InGaN. I also have done some work studying mechanical deformations in ZnO. Our group also works extensively with LEDs and laser diodes, most recently being interested in UV light emission. The main experimental technique I use is cathodoluminescence, which is capable of providing information about e.g. band gap, defect states, strain, carrier lifetimes, and donor and acceptor energy levels. Our group also performs a significant amount of transmission electron microscopy. Additional tools we utilize include photoluminescence, atomic force microscopy, x-ray diffraction, Hall and Van der Pauw measurements, and Rutherford backscattering.
Journal papers/conferences etc.
1st author, in progress:
» Hydrogen-related deeply-bound excitons in Mg-doped GaN films,
» The effect of crystallographic orientation on the relaxation mechanism of nano-indentations of ZnO single crystals.
Co-author / Published:
» Effect of Growth Temperature on the Electron-Blocking Performance of InAlN Layers in Green Emitting Diodes, Appl. Phys. Ex. 3, 031003 (2010).
» Comparative study of InGaAs integration on bulk Ge and virtual Ge/Si(100) substrates for low-cost photovoltaic applications, Sol. En. Mat. & Sol. Cells 94, 2362 (2010).
» Effect of misfit dislocations on luminescence in m-plane InGaN quantum wells, Appl. Phys. Lett. 98, 261914 (2011).
Co-author / In progress:
» Role of p-InxGa1-xN Layer in Enhancing Hole Transport and Distribution in InGaN/GaN Multiple Quantum Wells of Visible III-Nitride Light-Emitting Diodes, submitted to Appl. Phys. Ex. 2011.

 

Nicole Kotulak, Ph.D.



University of Delaware
nkotulak@udel.edu

Advisor: Dr. Robert Opila
Thesis project:
My work utilizes modeling and simulation to improve understanding of solar cell devices designed around an ordered-disordered interface, drawing from device theory and informed by experimental data. The extension of this work is to chart a path for the hybridization of inorganic semiconductor device structures with organic structures. The initial devices considered are a-Si on Si heterojunction devices. The goal is to more fully understand the role of a-Si as a disordered material and, thereby, evaluate other disordered materials for their efficacy in replacing a-Si in such devices.Expertise:
» Liquid Phase Epitaxy
» Scanning Electron Microscopy with EDS
» Simulation and Modeling

Other projects:
Growth of GaP on Si via LPE
Journal papers/conferences etc.
» “Mechanism of Electrical Passivation of Si Surfaces with Quinhydrone”, Robert L. Opila; Yang, D.; Kotulak, N.; Costello, L.; Chhabra, B. – Presented at the 38th IEEE Photovoltaic Specialists Conference, 2012» “Wide Band Gap Gallium Phosphide Solar Cells”, Xuesong Lu; Huang, S.; Diaz, M.B.; Kotulak, N.; Hao, R.; Opila, R.; Barnett, A. IEEE Journal of Photovoltaics, 2(2): 214-220, 2012.» “Quantum Efficiency Model Driven Design for wide band gap gallium phosphide solar cells”, Xuesong Lu; Diaz, M.; Kotulak, N.; Opila, R.L.; Barnett, A. – Presented at the 37th IEEE Photovoltaic Specialists Conference, 2011» “Growth of Gallium Phosphide on Silicon for Very High Efficiency Solar Cells”, Martin B Diaz, Nicole A Kotulak, Susan R Huang, Robert Opila, Allen Barnett – Poster presented at the 2010 Energy & Sustainability Conference, University of Delaware, Newark, Delaware, September 2010

 

Jongwon Lee, Ph.D.



Arizona State University
Ph.D. Student
jlee159@asu.edu

School of Electrical, Computer, and Energy Engineering
Advisor: Dr. Christiana Honsberg
Thesis project:
» The Development of Novel Thermodynamic Limit Modeling for future generation solar cells
» The Development of Si-Nanostructured Solar Cells
Expertise:
Matlab, Spectre for analog integrated circuit design, Electron Beam Lithography (2 year experience), MA-6 Aligner, Oxford Etcher

Other projects:
Solar Cell Modeling
Journal papers/conferences etc.
» Jongwon Lee and Christiana Honsberg , “The Detailed Balance Efficiency Calculations of Multiple Exciton Generation Photovoltaic Devices Under Concentrated Light”, presented at 2010 MRS spring meeting, San Francisco.
» Jongwon Lee and C. Honsberg, “Detailed balance calculations of multiple exciton generation and Tandem Hybrid solar cells,” in 2010 35th IEEE Photovoltaic Specialists Conference (PVSC), 2010, p. 002932–002937.
» C. B. Honsberg, S. P. Bremner, J. Lee, A. J. Bailey, and S. N. Dahal, “Hyrbid Advanced Concept Solar Cells,” presented at the Conference Record of the 37th IEEE Photovoltaic Specialists Conference, Seattle, WA, USA, 2011.
» J. Lee and C. B. Honsberg, “Thermodynamic Limits of Hybrid Photovoltaic Systems Using Multiple Junction Solar Cells with Carrier Transitions at Intermediate Band,” presented at the Conference Record of the 37th IEEE Photovoltaic Specialists Conference, Seattle, WA, USA, 2011.
» J. Lee and C. B. Honsberg, “Limiting Efficiencies of Intermediate Band Solar Cell Assisted with Multiple Exciton Generation,” presented at the Conference Record of the 37th IEEE Photovoltaic Specialists Conference, Seattle, WA, USA, 2011.
» J. Lee and C. B. Honsberg, “The thermodynamic limits of tandem photovoltaic devices with intermediate band,”Proceedings of SPIE, vol. 8256, no. 1, p. 82560Q–82560Q–12, Feb. 2012.
» J. Lee and C.B. Honsberg, “Limiting Efficiencies Over 50% Using Multijunction Solar Cells with Multiple Exciton Generation”, presented at 38th Photovoltaic Specialists Conference, Austin, 2012
» J. Lee and C.B. Honsberg, “Theoretical Analysis for Intermediate-Band and Tandem Hybrid Solar Cell Materials”, presented at 38th Photovoltaic Specialists Conference, Austin, 2012

 

Guy V Pickett III



Arizona State University
M.S. Student
gpickett@asu.edu

School of Electrical, Computer, and Energy Engineering
Advisor: Dr. Stuart Bowden
Phone: (623) 332-2081
Thesis project:
The goal of my research is to identify the loss mechanisms present in the solar cells fabricated in the student-led pilot line at the Solar Power Lab. It is my goal to reduce the effect of these losses on the cells produced in the baseline process at the SPL.
Expertise:
Optimization of p-n junction screen printed solar cell fabrication processes; solar cell characterization

Other projects:
Currently working on reducing shading of the cell by increasing the aspect ratio of the front Ag contacts during printing.

 

Vivek Sharma, Ph.D.

Tim Reblitz

Arizona State University
vivek.sharma.1@asu.edu

School of Electrical, Computer, and Energy Engineering
Advisor: Dr. Stuart Bowden
Phone: (480) 727-0702
Thesis project:
Vivek is working on characterization and comparison of silicon nitride (SiNx) anti-reflection films on crystalline silicon solar cells. His primary research is focused on the study of charges present in silicon nitride films and its characterization using C-V, C-T techniques. He also works on performance evaluation and analysis as well as quantification of loss mechanisms of large-scale photovoltaic systems.
Expertise:
» Ellipsometry (VASE), FTIR, RBS/ERD, Photoconductance, C-V, C-T, I-V, QE, Four Point Probe, PC1d.

Journal papers
» N. Chandra, V. Sharma, G.Y. Chung, D.K. Schroder, “Four-point probe characterization of 4H silicon carbide”, Solid-State Electronics, Volume 64, Issue 1, October 2011, Pages 73-77,
» Vivek Sharma, Adam Bailey, Bill Dauksher, Clarence Tracy, Stuart Bowden, and Barry O’Brien, “Characterization and comparison of silicon nitride films deposited using two novel processes”, J. Vac. Sci. Technol. A 30, 021201 (2012),
Conference papers
» Sharma, Vivek; Bailey, Adam; Dauksher, Bill; Tracy, Clarence; Bowden, Stuart; O’Brien, Barry; “Characterization and comparison of silicon nitride films deposited using two novel processes”, 37th IEEE Photovoltaic Specialists Conference (PVSC), Seattle, 2011, Page(s): 002206 – 002211 DOI: 10.1109/PVSC.2011.6186395,
» Vivek Sharma, Stuart Bowden “Performance and effect of dust storm on 10 MW grid connected PV systems installed at ASU” 38th IEEE Photovoltaic Specialists Conference (PVSC), Austin, TX, 2012
» Joseph Kutiche, Vivek Sharma et. al, “Statistical analysis of commercial c-Si PV module photovoltaic efficiency distribution over 10-years period” 38th IEEE Photovoltaic Specialists Conference (PVSC), Austin, TX, 2012

 

JeaYoung Choi



Arizona State University
Ph.D. Student
jchoi52@asu.edu

Advisor: Christiana Honsberg
Phone: (480) 251-6093I am working on organic surface passivation for silicon solar cell which has a purpose to reduce the manufacturing cost of solar cell. In addition, I am also doing nano-structured silicon solar cell.

(Graduated) Undergraduate Student Researchers

Yan Chen



Arizona State University
Yan.Chen.7@asu.edu

School of Electrical, Computer, and Energy Engineering

Matthew Erdman



University of New Mexico
merdman@ece.unm.edu

Advisor: Dr. Olga Lavrova
Phone: (505) 554-5264

Matthew Erdman is currently an undergraduate student at the University of New Mexico and will be graduating from his undergraduate studies in Spring of 2013. Matthew is currently involved with ASUNM’s Solar Decathlon team, is the lead student project manager for UNM’s ECE solar system installation, and is a consult for a solar installation company located in Albuquerque, New Mexico. As a consult Matthew has designed and managed the installation of numerous thermal solar systems, and over 250 kilowatts of on-grid, off-grid, and hybrid solar photovoltaic systems. Matthew looks forward to continuing his graduates studies at UNM in advanced solar cell materials.

 

Camden Kirkland



University of Houston
camdenkirkland@hotmail.com

Advisor: Dr. Alex Freundlich
Phone: (713) 870-2366

Hi, my name is Camden and I’m an undergrad at UH involved with chemistry and chemical engineering in PV. I have been researching with the Center for Advanced Materials since December of 2011 and have been intimately involved with MBE and CBE growth techniques as well as a smattering of different characterization techniques. My next project will involve quantum well growth using CBE as a part of the MENTEX program at UH. I look forward to the opportunity of creating and successfully defending a thesis in my undergraduate career, and I am looking at several programs for graduate school.

 

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