The most common types of solar cells in use are crystalline silicon (c-SI) and thin-film (TF) cells, with c-SI being the most common due to its high availability and efficiency. Though less efficient and not quite as abundant as c-SI, TF solar cells are moving forward and some in the market believe they will soon surpass c-SI in terms of both cost and performance.
In no ways a stranger, yet less present in the spotlight, organic solar cells offer a lot of promise. They employ carbon-based compounds (organic molecules) to absorb light and generate voltage.
Currently deployed in smaller applications, organic solar cells offer many advantages over popular c-SI components. For one, organic cells are easier and more economical to manufacture, therefore making overall processing significantly less expensive. Other attractive aspects of organic solar cells include a wide choice of production methods because organic materials are compatible with a variety of substrates, customizable molecular features, highly flexible, and light weight. Of particular note for environmental concerns, manufacturing organic solar cells requires less energy than inorganic components.
Unfortunately, similar to TF cells, the downside of organic solar cells is efficiency: 5%. Currently available c-SI panels are exceeding %15 to 25% and TF components are rapidly gaining momentum. But all things are possible and open to change.
When it comes to technology, game changers are ever present. Just last week, Heliatek GmbH set what is being called a world record for organic solar cells. SGS, an accredited and independent testing facility, found the company’s latest organic photovoltaic (OPV) cells to exhibit a 10.7% cell efficiency per 1.1 cm2as well as impressive low-light and high-temperature performance.
Heliatek's organic photovoltaic (OPV) cell sets a world record for efficiency at 10.7%.
Heliak attributes this feat to a family of small organic molecules called oligomers, which the company developed and synthesized. Heliatek claims to be the only solar company in the world that uses the deposition of small organic molecules in a low temperature, roll-to-roll vacuum process.
Measurements
SGS performed efficiency measurements under standard testing conditions and at low light and high temperatures up to +80°C. In addition to the record 10.7% cell efficiency, measurement results for low light established that the efficiency not only remains constant, but even increases gradually. At an irradiation of 100 W/m² efficiency is 15 % higher compared to standard efficiency measured at 1,000 W/m². Also, high-temperature measurements confirmed constant efficiency. According to the company, this is unique in that traditional solar technologies exhibit efficiency drops of 15% to 20% under rising temperatures.
Reaping another advantage, this consistency of efficiency also translates into a higher harvesting factor under actual environmental conditions. Outdoor tests indicate the harvesting factor of Heliatek's organic solar cells is 15 % to 25 % higher than c-SI and TF solar.
Product
So with this great breakthrough, when will we see some product? Thibaud Le Séguillon, CEO of Heliatek pipes, “Thanks to the close cooperation between our research teams in chemistry and physics, we are now on our path to achieving 15 % efficiency within the next few years.” Heliatek is presently assembling its first roll-to-roll manufacturing line in Dresden, Germany, and is expected to launch production in the third quarter. Go OVPs!