By Yanting Yin
I really enjoy travelling around Australia, the experience is always cool and different. One thing that can be frustrating however is narrow, single-lane highways. It is very easy to get stuck in traffic on these roads, and no one likes the feeling of overtaking a large truck on such roads. The traditional use of metal oxide materials, such as titanium dioxide, in organic photovoltaic devices (OPVs) results in this kind of single lane for charge transport. It is not difficult to imagine how this difficulty in charge transport can result in efficiency losses.
What if there could be a wide flyover, with much higher speed limits, in addition to the existing lanes? Then we are able to drive on both lanes with no traffic jams, and no dangerous overtaking. While this could be beyond the government’s budget for many roads, something similar is being explored in next generation solar power, a “flyover” which is created by the careful selection and treatment of materials, resulting in much more efficient charge transport.
When designing this “flyover” for organic photovoltaics, we need to ensure that the energy levels in the chosen materials result in efficient transport. If we return to the analogy of a car on the road, this would be making sure the entry ramp is accessible and that the flyover has an achievable slope. In my research, this means carefully selecting which metal oxides will be used, measuring their energy levels and determining if other surface treatments might be required. All of these efforts contribute to the establishment of alternative charge transport pathways in an OPV, leading to an enhancement of the device output.