Panchromatic solar cells for better conversion of solar energy
In DSSCs, a photoactive dye absorbs photons and uses their energy to excite electrons. The excited electrons are usually transferred into a nanocrystalline titanium dioxide layer, but the high-temperature processing required for titanium is not compatible with low-cost fabrication methods and the use of dyes typically hinders panchromatic solar harnessing. The project NANOMATCELL (Novel environmentally friendly solution processed nanomaterials for panchromatic solar cells) invented new materials and architectures for solution processed solar cells to address those challenges. Using abundant and/or non-toxic nanomaterials, the semiconductor achieved optimal band gap and a very high absorption coefficient to harness the maximum amount of sunlight possible. Project partners developed novel strategies for synthesis, growth and doping of semiconductor nanocrystals, nanowires and perovskites. They included a new pathway for environmentally friendly colloidal semiconductor nanocrystals with tuned band gaps and very high absorption coefficients. The design of perovskite materials was optimised using specially developed hole and electron acceptor materials. New dyes were also developed for short wavelengths and for enhanced absorption in the near-infrared range in order to take advantage of a larger portion of the spectrum. A record performance colloidal quantum dot solar cell was developed with exceptional photostability. In addition, the first high efficiency (9.6 %) and highly photostable PbS QD solar cell was shown. The record performance of the perovskite solar cells achieved – 20 % – has rendered the EU as one of the leaders in this research roadmap. Researchers also demonstrated the first ever solid-state solution-processed at low temperature and ambient conditions inorganic solar cell based entirely on non-toxic Restriction of Hazardous Substances (RoHS) compliant materials. NANOMATCELL therefore made a significant impact by showing for the first time that outstanding performance can be achieved using environmentally friendly nanomaterials. This will pave the way for immediate commercial uptake and introduction on a broader scale (including wearable platforms, building integrated-PVs and distributed power grid networks) without regulatory concerns on closed-cycle recycling processes. The scientific results of NANOMATCELL were published in leading peer-reviewed scientific journals. Therefore, the initiative has been instrumental in making Europe a major player in research into solution processed thin film solar cells, successfully developing record performance solar cell devices in their corresponding classes.
Keywords
Dye-sensitised solar cells, photoactive dye, photons, fabrication, NANOMATCELL, titanium dioxide, nano crystals, nano wires, photostable, Restriction of Hazardous Substances
