Scientists from the University of Cambridge have discovered a faster mechanism by which organic materials can redistribute sunlight energy. This could provide the key to unlocking a new generation of organic solar cells.
Research into solar power and improving its efficiency is important. The conversion of sunlight into electrical power is an optimal means in many parts of the world in the bid to slowdown the rate of climate change.
The majority of solar panels are formed from silicon and they are expensive to produce. As an alternative technological path, organic solar cells (formed from materials derived from plants and animals) offer a lower cost solution and the panels fashioned will be considerably lighter in weight, with the added boots of being flexible,.
What is holding organic solar cells back is where the sunlight-to-electricity efficiencies of silicon-based solar panels continue to be more efficient.
This could change with the discovery of a new means for energy to move in organic materials at a speed up to 1000’s of times faster than normal. This is a process termed “transient exciton delocalization”.
At the heart of the technology are nanofibers fashioned from a sulphur and carbon-based polymer. These fibres enable scientists to precisely control the position of each of the atoms in the organic nanofiber. From this, it is possible to develop improved materials.
In trials, the researchers used transient-absorption microscopy to create ‘films’ of the energy transport. They were then able to observe the energy movement and the resolution was recorded at around a single femtosecond, or 0.000000000000001 of a second. This is the equivalent to a film with a frame rate of 1 million billion frames per second. Understanding this will provide the baseline for the next wave of solar technology.
The research has been published in a paper titled “Efficient energy transport in an organic semiconductor mediated by transient exciton delocalization” (in the journal Science Advances).
In related news, it has been found that the photovoltaic effect of ferroelectric crystals can be increased by a factor of 1,000 provided that three different materials are precisely arranged periodically in a lattice. This development can also aid in the acceleration of solar energy capture, storage and deployment.
These advances can help support the drive to increase the take-up of solar technology. However, advances in technology are not the only measures needed. Societal shifts and nudges are needed. In terms of what might motivate people to adopt solar power, a review by Potsdam Institute for Climate Impact Research found that the number of solar panels located within shortest distance from a house is the most important factor in determining the likelihood of that house having a solar panel. This finding comes after the data has been normalized for socio-economic and demographic variables.
The review appears in the journal Science Advances, headed “Decay radius of climate decision for solar panels in the city of Fresno, USA.”
