The global climate crisis is a growing, modern problem, requiring new, revolutionary technology to solve it. One such technology is the solar cell, which we can use to harvest light energy to generate electricity, without creating emissions, or having a large environmental impact. Current commercial, silicon-based solar panels typically have power conversion efficiencies ranging from 15-20 %, meaning up to one fifth of the light hitting a solar panel is transferred into usable energy. However, these panels are expensive, fragile, rigid and not very efficient. An alternative to these types of solar cells are dye sensitised solar cells (DSSCs) which utilise a molecular dye to absorb light energy. These cells are much less expensive to make, are flexible and printable, and transparent, meaning they can be used in windows for example. However, scientists are yet to find a DSSC which is able to compete with the efficiency of other forms of solar cells.
My research delves into the molecular electronics of donor-acceptor dyes: both organic and inorganic compounds which can be used in these DSSC technologies, along with OLEDs and molecular sensors, owing to their unique photophysical and electronic characteristics. In order to find suitable dyes for these technologies, an extensive library of compounds must be formed to discover compounds which cater for different technological requirements. In my research, I investigate the electronic excited state properties of many donor acceptor dyes utilising, vibrational and electronic spectroscopic techniques. Such as absorption, emission, resonance Raman and transient spectroscopies.
Resonance Raman is similar to measuring typical Raman vibrational spectroscopy, however, instead of using a low energy IR excitation laser, higher energy lasers within the UV-vis range are used to measure an analyte. When the excitation laser wavelength corresponds to an electronic absorption of the analyte, there is specific enhancement of vibrational modes which mimic the geometry changes occurring upon the electronic excitation. This allows us to investigate these geometry changes, and how electrons move about the compound’s framework. In conjunction with this, we use DFT computational methods to aid these investigations.
