A new semiconducting plastic is set to bring low-cost, organic solar cells closer to the marketplace. UK start-up Ossila has now begun supplying the polymer PCDTBT to academic and industrial researchers. While organic photovoltaics have been muted for several years, there are scant few materials available commercially, off the shelf — most being based on a material called P3HT.
‘The reason we’re so excited about this [PCDTBT] is because it combines better efficiency, it’s a much more stable polymer and it’s also more manufacturable,’ said managing director Dr James Kingsley.
These three factors are key to making organic photovoltaic electricity a commercial reality for a range of applications, he added.
In lab tests, PCDTBT has demonstrated an almost 50 per cent improved efficiency in terms of energy conversion over P3HT. In addition, while P3HT takes several minutes to dry during manufacture, PCDTBT can be processed far quicker. Unlike P3HT, the newer polymer is also stable in air.
‘If you’ve got something that’s up on the roof for 10 years with sheeting rain, you want something that’s stable,’ said Kingsley. ’Also, you don’t want to put your entire factory in a nitrogen-free or oxygen-free environment; this material can be processed without a glove box.’
Some of the applications opened up by better organic photovoltaics include ‘roll-out’ mats for consumer electronics, semi-transparent solar windows and the roofs of large commercial sheds, such as those that supermarkets occupy.
‘The roofs of those aren’t strong enough typically to hold huge weights of glass-panel photovoltaics, whereas organic photovoltaics are thin, flexible and lightweight and therefore can be deployed here,’ said Kingsley.
Ossila has begun to supply PCDTBT commercially and Kingsley hopes this will democratise the marketplace away from the bigger players.
‘There are a number of other people around the world who are developing these materials, but most of the time they don’t supply them to other people; they just keep them to themselves or give them to selected partners,’ he added.
Ossila is currently working with Polysolar, a small company in Cambridge that is developing semi-transparent solar windows.