Polymer solar cellsEva Bundgaard
The material used to absorb the solar light in organic solar cells, is an organic material such as a conjugated polymer. The basic principle behind both the polymer solar cell and other forms of solar cells, however, is the same, namely the transformation of the energy in the form of electromagnetic radiation (light) into electrical energy (a current and a voltage), i.e. a physical phenomenon called the photovoltaic effect. This energy conversion is possible with the use of semiconductors. Semiconductors are a group of materials which are in-between an insulator and a conductor. Silicon is a classic example of a semiconductor and is also the material that is currently used in most solar cells, i.e. the first generation solar cells. The fact that polymers can behave as semiconductors is a discovery which Alan J. Heeger, Alan MacDiarmid and Hideki Shirakawa received the Nobel Prize in Chemistry for in the year 2000. This discovery of conjugated polymers being able to transfer electrons upon doping with iodine made it possible to prepare solar cells from polymers and thereby a new research area was born.
Polymer solar cells have for a long time lagged behind traditional solar cells on both performance and stability. However, they have always had a potential advantage; that is their ability to be produced from solution. This means that they can be printed or coated, instead of using expensive vacuum deposition as for the first generation silicon solar cells. Today, performances of 10% have been demonstrated for polymer solar cells.DOI:10.1002/pip.2163 The lifetime has also improved considerably and plastic solar cells with a shelf life of several years have been demonstrated.DOI:10.1016/j.solmat.2013.04.024DOI:10.1002/pip.794 In addition, large scale production of polymer solar cells is today to some extent a reality, as demonstrated by for example the freeOPV initiative.DOI:10.1002/ente.201300057 In this section you can learn why we think polymer solar cells are the future, how they work, and how they are made..https://www.coursera.org/course/opv http://en.wikipedia.org/wiki/Organic_solar_cell http://en.wikipedia.org/wiki/Polymer_solar_cell "Plastic Solar Cells", Christoph J. Brabec, N. Serdar Sariciftci, and Jan C. Hummelen, Advanced Functional Materials 2001 Frederik C. Krebs, Polymer Photovoltaics: A Practical Approach, SPIE Press