Developing Thin-Film Photovoltaics from Nontoxic and Earth Abundant Materials

by Andrea X. Foo

Mentor: Luke Davis, Chemistry; Funding source: Provost’s Office

fooandreax_38412_2253545_Summer-Scholars-poster

With climate change gradually posing a greater problem everyday, it is imperative for the world to transition into a future where the energy source is based on renewable sources. The most abundant source of renewable energy is the sun, and so solar technology thus far holds the most promise. With solar power being one of the most promising renewable energy technologies, an abundance of research efforts has gone into developing solar technologies to help generate efficient and low-cost solar cells with the goal of widespread use. Thin film photovoltaic (PV) cells have the highest potential to provide high production capacity at reduced material and cost consumption in the manufacturing process. PV cells are constructed by a combination of different semi-conductor layers that directly convert sunlight into electricity.

Although silicon-based devices of about 20% efficiency are present on the market right now, the cost to manufacture and install them remains too high for their adoption to be sufficiently widespread to replace the use of fossil fuels. Production and installation cost of solar technology remains a prominent concern. A global energy transition forecast by DNV GL predicts that by 2050, the electricity demand is expected to double. The amount of photovoltaic (PV) derived energy is predicted to go up by 20x between now and then, indicating a demand for more PV cell installations. IRENA’s Remap analysis shows that solar PV power installations could grow almost six-fold over the next ten years, reaching a cumulative capacity of 2840 GW globally by 2030 and rising to 8519 GW by 2050. This implies total installed capacity in 2050 almost 18x higher than in 2018. With such high demand, less expensive in production and more efficient PV cells will be greatly beneficial to the community at large.

Current commercial thin film PV technologies are primarily made up of Cadmium Telluride and Copper Indium Gallium Diselenide. Unfortunately, these commercial thin film technologies are based on rare elements, rendering it extremely costly for widespread use. Despite technological advancements thus far, solar cells still face many obstacles with cost, efficiency, and safety in production being some of the largest issues. The current best thin-film PV options require toxic or rare elements. Given these limitations, the current challenge is to prepare thin films of light absorbing materials with control over the possible defects.

My research this past summer on photovoltaic cells aimed to explore this issue by modelling different thin film PV devices to find the best possible combinations of materials that can be used to create an efficient device.     I used SCAPS, a modeling software, to simulate different photovoltaic devices with the goal of finding the highest efficiencies possible with different parameter combinations. These findings are essential information to my continued research when I return back to campus and continue to create physical photovoltaic devices in the Davis Lab as I will then be able to construct devices with the highest efficiencies possible based on modeling results.

The applications following my research has potential to impact the everyday lives of people as once low manufacturing cost solar energy has been harnessed, solar energy can be used by more people. With solar cells being clean and renewable energy, the widespread use will thus greatly benefit the environment and limit climate change. Photovoltaics make good use of the energy of the sun and convert it into electricity that can be used to make households greener and more environmentally friendly. I hope to continue my work when I return to the Davis Chemistry Lab on campus. Until then, please enjoy what I have done so far!