Photovoltaics is a broad field that spans materials to systems and includes mature technologies like crystalline silicon, new ones like organic solar cells, and exploratory, third generation concepts. Success requires contributions from chemistry and materials science, to device design and characterization, to manufacturing and system level considerations. Theory, modeling, and simulation is well-established in photovoltaics, but the field is fragmented according to the interests and disciplines of researchers and the technologies being explored and lacks the critical mass to be effective. The workshop, Challenges in Photovoltaic Science, Technology, and Manufacturing: A workshop on the role of theory, modeling, and simulation will provide an opportunity for researchers from academia, industry, and the national laboratories to identify ways to advance the field of photovoltaics. Multiscale modeling and simulation is a pervasive challenge in science and engineering. Addressing this challenge for photovoltaics, will contribute to success in other disciplines. The workshop will identify models for universities to collaborate across disciplines and for universities and companies to pursue collaborative research that will have broad impact beyond photovoltaics.
There is a great need for reliable, renewable, environmentally friendly, and economic sources of energy. Photovoltaics (solar cells) are already beginning to play an important role, and with continued progress can play a much larger role in the future. To do so, efficiencies of existing technologies must be substantially improved, and new technologies identified, demonstrated, and developed. To achieve these ambitious goals, theory, computer modeling, and simulation (TMS) must play a larger role. The goal of this workshop was to bring together a broad range of experts with extensive experience in photovoltaics to discuss strategies to increase the effectiveness of theory, modeling, and simulation for solar cells. Just as TMS transformed microelectronics, it has similar potential for transformative impact on photovoltaics. The workshop objectives were to: 1) Identify key successes and future technical challenges, 2) Discuss the current status of TMS in photovoltaics, 3) Identify critical challenges and key opportunities for TMS, 4) Discuss models for multi-disciplinary research, software development and dissemination, and industry-university cooperation, and 5) Identify key opportunities for TMS to advance PV research and development. The unique aspect of this workshop was its breadth. It was not directed at the modeling community or at a specific technology, but, rather, engaged the broad PV community. Participants came from academia, national laboratories, and industry and represented a wide range of expertise, disciplines and technologies. The workshop provided a forum for lively discussions about how TMS can more effectively address the challenges and opportunities in photovoltaics. For the complete workshop agenda and to access most of the presentation made, see: https://nanohub.org/groups/PVWorkshop. The workshop identified some key opportunities for TMS. First, it can help create the design rules needed for an "end-to-end," "materials-to-modules" approach for all major PV technologies. At the basic level, such a framework would encompass atomic-scale behavior both quantum mechanically and semi-classically to help predict basic optical, mechanical, and electronic materials properties, including the effects of impurities. At a higher level, the overall desired device morphology and performance will be important. Making accurate predictions will require appropriate semi-classical 3D models for photon management and electronic transport. High efficiency cell designs will also need to account for additional physical phenomena such as photon recycling and heterojunction interfaces. Successfully packaging solar cells into high-performance modules is a challenging but crucial follow-up task. Creating a simulation tool that accounts for the heterogeneous and variable nature of the module sub-components will be necessary. Finally, manufacturing high-quality solar cells in an affordable, reliable and scalable fashion is critical and will require the capability to predict mesoscale morphology under high-throughput deposition and aging. As a pre-competitive activity, TMS should be explored by multi-disciplinary teams from academia and national labs in high-risk, high-reward investigations. Areas of interest will include characterization; creating central data repositories for PV material parameters; and educating and inspiring the next generation of scientists. Industry should adopt good models in order to perform better R&D, particularly improved characterization, modeling, and metrology; redesign processes and devices as appropriate to achieve sustainable profit margins.
