by Briton Lee
Recently, researchers were able to produce organic photovoltaic (OPV) cells in a way that can be scalable to an industrial level. One of the barriers facing the widespread adoption of solar power is the cost-prohibitive nature of its production. Additionally, the conditions used to create inorganic solar panels, such as crystalline silicon are harsh; for instance, they must be produced at very energy-intensive high temperatures. Organic solar cells are being explored precisely because the organic materials characteristic of the product have a low production cost, with the added benefit of being flexible. Some of the drawbacks of organic solar cells are that they are not as durable as inorganic solar cells, and have a lower conversion efficiency. These drawbacks are attenuated by the potential of both scaling up the efficiency of the cells and robust mass production of organic solar cells with minimal resource input. While it may have a relatively low conversion efficiency, we have to take into account the amount of energy it can potentially create relative to the energy input; the net return on energy is substantial.
The Andersen group is the first to demonstrate the successful production of roll-to-roll, contiguous solar cells and confirms the possibility of producing a high technical yield with relatively simple conditions. The way these cells are produced involves the “printing” of multiple layers (14 in this case) one over another extremely quickly. Each 14 layer section can be printed in 1 sec, ultimately achieving a printing rate of 1.3 meters per minute. It is interesting to note that the majority of the research in OPVs focuses on high conversion efficiencies in small photovoltaic regions, neglecting the efforts in optimizing the average performance of large area devices, the latter of which are more relevant to practical implementation. The variety of applications for OPVs, such as packaging, flexible screens, clothing, make this material extremely viable in industrial settings, and these findings take us one step closer to the reality of widespread solar energy.
Andersen, T. R. et al. 2014. Scalable, ambient atmosphere roll-to-roll manufacture of encapsulated large area, flexible organic tandem solar cell modules. Energy Environ. Sci. 7, 2925–2933 (2014).
Royal Society of Chemistry (http://www.rsc.org/chemistryworld/2014/06/roll-roll-flexible-organic-tandem-solar-cells)