Area 1 & 3: Anna Fontcuberta i Morral, École Polytechnique Fédérale de Lausanne, Switzerland

Dr. Anna Fontcuberta i Morral is a professor at EPFL, Switzerland. Her research interests concern novel materials and structures for next generation quantum technology and energy harvesting technologies.

Title: Compound Semiconductor Nanostructures: Synthesis & Sustainability Aspects

Abstract: Some compound semiconductors such as InGaAsP and GaAs are known to exhibit a high absorption coefficient in the photon energy of interest for solar energy conversion. Their commercial potential in terrestrial applications is reduced due to the scarcity and high cost of extraction of group III elements such as In and Ga. In this talk we present two paths to enable the use of compound semiconductors sustainable: (i) a strong reduction in material utilization by nanostructures design and (ii) the replacement of group III by group II such as zinc. The Zn-V compound semiconductor family exists in a variety of stoichiometries such as ZnP2, Zn3P2 and Zn3As2. Also, in this case we find nanostructures also provide a path to increase light collection [1]. We demonstrate how II-V compounds such as Zn3P2 exhibit one magnitude higher absorption coefficient than GaAs [2]. We explain how these materials can be fabricated with high crystal quality, opening the path for the creation of alternative and sustainable compound semiconductor solar cells [3-5].
[1] P. Krogstrup et al Nature Photon 7, 306 (2013)
[2] M.Y. Swinkels et al Phys. Rev. Appl. 14, 024045 (2020)
[3] S. Escobar Steinvall et al Nanoscale Horizons 5, 274-282 (2020)
[4] R. Paul et al, Crys. Growth. Des. 20, 3816–3825 (2020)
[5] S. Escobar Steinvall Nanoscale Advances, DOI: 10.1039/D0NA00841A (2020)

Area 2: Marika Edoff, Uppsala University, Sweden

Dr. Marika Edoff is a professor in Solid State Electronics and head of the Solar Cell Technology Division at the Department of Material Science and Engineering at Uppsala University, Sweden. She has been working in the CIGS research field since she began as a PhD student in 1991.

Title: The Future of CIGS–based Thin Films in Tandem and Bifacial Solar Cells

Abstract: With its high absorption coefficient, high efficiency, high stability and scalability the CIGS solar cell has shown industrial maturity. In addition to applications in building integration, where CIGS has unique features, such as low weight and possibilities for semi-transparency, future promises include CIGS-based absorbers in tandem solar cells. The possibility to vary the bandgap of CIGS enables different configurations such as CIGS-silicon, perovskite-CIGS or CIGS-CIGS tandems. New developments including Ag alloying for efficient solar cells with large bandgap open new possibilities for top cells in tandems. Sulfur alloying, also for increasing the bandgap is another possibility. Transparent contacts are necessary for tandem top cells and do also allow bifacial applications. The challenges related to replacing the well-known Mo-based back contact are non-trivial but successful development of reflecting back contacts indicates ITO or In2O3:H as suitable candidates. In this talk a review of the latest developments in alternative back contacts as well as CIGS alloying will be given.

Area 4: Delfina Muñoz Cervantes, National Institute for Solar Energy, France

Dr. Delfina Muñoz, is the principal researcher in the heterojunction solar cells laboratory at CEA-INES. After finishing her studies in industrial engineering in Barcelona in 2003, she started the heterojunction solar cell adventure in her PhD at Universidad Politécnica de Cataluña developing laboratory scale solar cells, processes and improving characterization skills (with a stage at LPICM Paris). In 2008, she joined CEA-INES as a postdoc and since then, she has been improving heterojunction technology from the lab to the fab. She obtain her permanent position at CEA-INES in 2010 and in 2012, she became the leader of the heterojunction team. She has been involved in several European (FP7, H2020) and French research projects (ANR) and she was the coordinator of the successful FP7 HERCULES project with the first heterojunction industrial transfer in Europe. She has more than 40 WoS publications and more than 60 conference presentations related to heterojunction technology. Last years, she has been involved more in industrial-related projects (Meyerburger, EGP, H2020 AMPERE) with successful technology transfer and develops the analysis of the technology not only at the cell but also at the module and system level. She is also involved in the Chilean ATAMOSTEC project related to reliability of photovoltaics in desert areas and evaluating the performance of the different technologies on hard conditions.

She is in the steering committee of the nPV and tandemPV workshops; she is reviewer in several high impact journals and conferences where she is chairing and invited regularly. She is also in the strategic team on European projects of CEA and works in the roadmap definition of next PV technologies as tandem photovoltaics.

She still combines her project activity with the laboratory, directing PhD students and developing heterojunction solar cells for the next tandem photovoltaic technology.

Title: Silicon Heterojunction Technology at CEA: What We Learnt During 15 years Development?

Abstract: In this talk, an overall vision of the development performed the last 15 years at CEA-INES will be presented. From the first R&D tests passing through the pilot industrialization and the technological transfer to EGP through the different European projects like HERCULES and AMPERE, results will be shown up to the outstanding 25% efficiency in full wafer heterojunction and their module integration.

Area 5: Joseph Berry, National Renewable Energy Laboratory, USA

Joseph Berry is a principal scientist at the National Renewable Energy Laboratory working on halide perovskite solar cells where he leads the US Department of Energy (DOE) Solar Energy Technology Office’s SETO core technology program, “De-risking Halide Perovskite Solar Cells” at NREL. He is also principal investigator on the NREL lead Department of Energy, Center for Hybrid Organic Inorganic Semiconductors for Energy (CHOISE) Energy Frontier Research Center, exploring basic aspect of hybrid materials and is the director of the newly formed U.S. Manufacturing of Advanced Perovskites (U.S. MAP) consortium a collaboration between industry academia and the national labs to bring perovskite technologies to market.

Title: What Precisely is the Path to a Printable Terra-Watt Scale PV Technology?

Abstract: Photovoltaics devices based on metal halide perovskite (MHP) absorbers have reached outstanding performance over the past few years, surpassing power conversion efficiencies of over 25% for lab cells and with larger area devices in excess of 18%. But what precisely are the key physical features that result in the amazing performance? What are the key materials and device metrics that we can characterize in 5 minutes to provide a prediction of a 30-year lifetime in real world operation? This talk will discuss the first question, but unfortunately not provide clear answers to the second as addressing it is the topic of considerable ongoing R&D efforts. What the present thoughts are regarding what in a perovskite solar cell needs to be characterized, at what length scales and under what set or sets of conditions will also be discussed in some detail. Similarly, topics related to the closely coupled questions of what are the critical aspects of process, sustainability and manufacturing required to ensure produced materials with large-scale high-speed processes can live up to the promise MHP photovoltaics provide, will be addressed.

Area 6: Laura Miranda Perez, Oxford Photovoltaics, UK

Dr. Laura Miranda Perez is been heading the materials and characterisation department at Oxford Photovoltaics since 2015. With more than 15 years of experience on perovskite materials, Laura’s expertise covers a broad range of materials and processes together with strong fundamental understanding on complex systems.

Area 8: Alison Lennon, University of New South Wales, Australia

Professor Alison Lennon is a Professor at the School of Photovoltaic and Renewable Energy Engineering at UNSW Sydney, Australia. Her research interests include silicon solar cell metallisation and interconnection and optical and thermomechanical modelling for photovoltaic modules. Since 2010, she has held research projects in this field of research with Suntech Power, Trina Solar and LONGi Solar. She also conducts research into high-rate energy storage, with a focus on lithium-ion batteries, and is working with battery manufacturers to develop new battery management systems

Title: The 'Nuts and Bolts' of Silicon PV Modules – Metal Contacts and Interconnection

Abstract: Although device physics enables us to explore fundamental limits of light energy conversion, the practical reality of low-cost silicon photovoltaic modules produced with a predictable electricity yield at scale and sustainably also requires an understanding of metal contact formation, optics, metal bonding, thermomechanical stress, durability and resource availability. This talk will explore the challenges facing solar cell metallization and interconnection in modules given the requirements of sustainability, low cost, high module area efficiency, predictable electricity yield and durability. Manufacturers are now servicing the demands of two market segments; rooftop and utility scale and the requirements of these two market segments are not always congruent. Placed on top of these demands, is the need to produce at low cost and at scale, the latter necessitating access to resources such as silver, copper and aluminium which are increasingly in demand in our transition to a renewable energy economy.

Area 11: Xiaoting Wang, BloombergNEF, USA

Dr. Xiaoting Wang joined BloombergNEF in 2012, currently conducting research as an energy specialist focusing on solar technology. Her routine research scope covers shifts in crystalline silicon module technology, perovskites, innovation in PV project design, construction, and maintenance. Xiaoting’s recent research topics have included integrated design of co-located PV and storage systems, and the economics of making hydrogen from renewables.

Area 12: Erica Mackie, GRID Alternatives, USA

Erica Mackie co-founded GRID Alternatives in 2001 and has developed it into a major national non-profit. As an engineer herself, Erica believes engineers have a key role to play in social justice.

Title: How Renewable Energy can be a Tool for Social Justice

Abstract: Renewable energy can drive economic growth and environmental benefits in communities most impacted by underemployment, pollution and climate change. Prior to the COVID-19 pandemic, solar energy was one of the fastest growing industries in the United States. GRID Alternatives has real world experience making renewable energy technology and jobs accessible to environment and economic justice communities. Through our hands-on training programs across the country, we have seen how real-world experience provides individuals with the skills needed to jump start a career. By partnering with community organizations, we have seen the positive impact that solar energy savings and cleaner air can have on individuals, families, and tribal communities. Erica will discuss success stories that GRID Alternatives has seen over the years, and what needs to be done to make renewable energy solutions accessible to and led by environmental justice communities. By including everyone in the clean energy economy, we can make sure that everyone benefits and is part of our transition to a renewable energy future. GRID Alternatives’ mission is to build community-powered solutions to advance economic and environmental justice through renewable energy.