Por Manuel Mendes (FCT NOVA, Universidade NOVA de Lisboa, Portugal).
Photovoltaic (PV) technology is currently in an embryonic stage, since there is still a long way to trailblaze to reach an optimized exploitation of the immense solar power available. Here we will cover some of the most exciting developments that are being cooked in the lab, but will find industrial application in a near future.
The first challenge of solar electricity is concerned with efficiency. For that, recent breakthroughs have been attained with the multi-band PV concept realized with perovskite solar cells impregnated with colloidal quantum dot arrays, which can potentially reach 50% solar-to-electricity efficiency with single-junction devices, thereby surpassing the traditional Shockley-Queisser limits.
The second challenge is cost-effectiveness. To tackle that, photonic structures with dimensions comparable to the sunlight wavelengths are now regarded as the preferential solutions to enhance the power/cost ratio of thin photovoltaic devices via light trapping. For instance, we have designed photonic thin-film cell architectures capable of efficiency improvements up to 100% with respect to planar reference solar cells!
The third main challenge of solar electricity has to do with Storage. In that respect, artificial photosynthesis is one of the best ways to protect the environment while producing high-density fuels (e.g. Green Hydrogen or even Natural Gas). We will present Photovoltaic-Electrochemical (PV-EC) integrated systems, enhanced via light management (photonic) strategies, capable of converting sunlight into such convenient gaseous fuels with high efficiency.
