The OPV Workshop “A New Technology to Market” Congress was held in Barcelona on the 7th of October to highlight the innovations and commercialization pathways of Organic Photovoltaic technologies.
The OPV Workshop had the goal of taking the pulse of the sector, both from academic and business point of view and present the latest developments achieved in OPV technologies. Researchers, prescribers and potential investors were invited to attend the workshop to discuss and comment on the barriers and realities of these innovative technologies.
The unique properties of the active material used to capture the sun’s photons in Organic photovoltaics (OPV), are light weight, flexibility, transparency, sensitivity to low light levels or non-direct sunlight, and an ability to be processed using printing or coating techniques that can be implemented in a roll-to-roll fabrication. These attributes make OPV one of the most attractive PV technologies for integration into everyday life. When compared to their inorganic counterparts, it is particularly interesting that OPV cells can be used in transparent building elements introducing a minimal change to the visual appearance of such elements. In fact, it has been recognized that a major area for application of organic solar cells may be in building integrated energy production technologies.
Transparency is intrinsic to the active layer in many of the organic based photovoltaic technologies. The low charged carrier mobility in donor and acceptor organic materials prevents, in many such cases, the use of thick active layers that would otherwise lead to very efficient photon harvesting. Such low charge mobility and its associated transparency, which is seen by many as the Achilles heel for the development of a commercial organic based PV technology, may turn out to be its strongest asset for competing in the market for the photovoltaic production of electrical energy.
However, there are several scientific and technical issues that must be addressed before such OPV technology can become commercially applicable in any kind of building integrated energy production element. Although the power conversion efficiencies (PCEs) measured are considerably high, a drop of least 20% in conversion efficiency is likely when up-scaling from laboratory cells to modules. At present the fabrication procedure followed for solar devices includes several steps that require high vacuum thermal evaporation or sputtering, and it is likely that this would preclude a favorable cost efficiency ratio when this technology is compared to thin-film inorganic based technologies that also have the potential to become transparent. In addition, there are no systematic studies that demonstrate the performance stability of OPV devices over the long timescales required for the majority of building elements. Finally, it will be necessary to address other relevant issues related to the product life cycle, such as safe disposal and recovery of the materials used in the fabrication of OPVs. The Topic 4.0-2 “Innovative materials for efficient, stable and cheap organic photovoltaic cells”, from the FP7-NMP-2013-SMALL-7 call provides an excellent framework to develop efficient OPV technologies and marketable BIPV products.
During the last two years there has been a dramatic turnaround for: The level of performance of opaque OPV device in terms of efficiency as well as other very relevant aspects, such as processing or stability, and the semi-transparency and potential for integration in buildings for an organic based PV technology. Record efficiencies have almost and the introduction of new concepts and nano-materials into the structure of transparent organic cells has significantly improved their future prospects for deployment in urban areas as a viable PV technology for the production electrical energy.