Team: 24
School: La Cueva High
Area of Science: Chemistry
Interim: Problem Definition:
Solar panel cells are a key, renewable source of energy for generating power, especially in space vehicles. The cells in space station solar arrays use the photovoltaic effect to convert light into electricity (Garcia, 2017). Photovoltaic cells mostly utilize visible light with longer wavelengths, such as light in the red or yellow range of the visible spectrum (Pius & Benaiah, 2015). In space, there is a much higher presence of ultraviolet (UV) light than on Earth due to a lack of a shielding atmosphere; however, not only are UV light waves difficult to harvest because of their high energy content, but they also degrade the physical composition of solar panels (National Aeronautics and Space Administration, Science Mission Directorate, 2010; Shamachurn & Betts, 2016). Space vehicles have a high reliance on solar panels for power but solar panels for terrestrial use are not built to endure the high intensity of UV light, given that their initial intent was to be used on Earth, a much more UV-protected environment.
Applying the concept of downshifting molecules, which is absorbing high energy photons and emitting them at a lower energy, may create new ways to collect and utilize UV. anti-B18H22 molecules, specific types of molecules that look promising for downshifting, are important as they have natural fluorescence, high photodegradation resistance, stability to radiation, high quantum yield and can undergo surface modification (Cerdán et al., 2015); however, the extent to which the anti-B18H22 molecules can downshift, the relationship between different modifications of the molecules and photoluminescent properties, and the geometry in which the ability to downshift is greatest are still unclear and are not cost-effective to synthesize and test in lab.
Problem Solution:
The synthesis of certain boron clusters in laboratories is time-consuming and sometimes not feasible, so simulations are critical to narrowing the range of possible derivatives for further examination in lab. As halogenation has shown potential for improving downshifting abilities, molecular models of anti-B18H22 derivatives modified with different halogens can be made. With programming, collected coordinates of the simulated molecules will be used to find energies of the most probable excited states for identifying likely absorption and emission wavelength, which can help explain current uncertainties and unknowns in anti-B18H22 molecules and modification effects.
Progress to Date:
So far, several molecular models of anti-B18H22 derivatives with varying combinations of Fluorine and Chlorine additions and different positions of halogenation have been made and optimized for its geometry. The files and bash scripts for compiling the coordinates and running the calculations on the supercomputers have also been completed and modified accordingly as calculations are being returned. With the results, the most probable absorption and emission wavelengths can be retrieved and compiled for analysis of trends.
Expected Results:
Simulations cannot guarantee exact absorption or emission wavelengths but they can show a trend in what increasing the number of halogens, changing the vertices at which the halogens are placed, and adding different halogens will likely do when molecules are actually synthesized in lab. Continued analysis could help find the optimal geometry of anti-B18H22 derivatives to have the greatest shift from absorption to emission.
References:
Cerdán, L., Braborec, J., Garcia-Moreno, I., Costela, A., & Londesborough, M. G. (2015). A borane laser. Nature Communications, 6(1). https://doi.org/10.1038/ncomms6958
Garcia, M. (2017, July 31). About the Space Station Solar Arrays. NASA. https://www.nasa.gov/mission_pages/station/structure/elements/solar_arrays-about.html.
National Aeronautics and Space Administration, Science Mission Directorate. (2010). Ultraviolet Waves. Retrieved June 23, 2021 from NASA Science website: http://science.nasa.gov/ems/10_ultravioletwaves
Pius, O. E., & Benaiah, B. (2015). Investigating the Wavelength of Light and Its Effects on the Performance of a Solar Photovoltaic Module. International Journal of Innovative Research in Computer Science & Technology (IJIRCST), 3(4). https://www.ijircst.org/DOC/111e277ced-3ebf-4c57-870d-bc4ec2c9151f.pdf.
Shamachurn, H., & Betts, T. (2016). Experimental Study of the Degradation of Silicon Photovoltaic Devices under Ultraviolet Radiation Exposure. Journal of Solar Energy, 2016, 1–9. https://doi.org/10.1155/2016/2473245
Mentors: Thomas Peng and William Bricker
Team Members:
Sponsoring Teacher: Creighton Edington