Jason Yoo-Pushing the efficiency limit of lead halide perovskite solar cells

Jason Yoo, a PhD candidate in Chemistry, gave the Nano Explorations talk on Thursday, May 21, 2020.
Lead halide perovskite solar cells are an emerging technology that can be solution processed to yield low-cost, light weight, and flexible photovoltaics. Much of the early work has been focused on developing device structures and processing techniques to improve light absorption and eliminate detrimental traps within the bulk of the perovskite active layer. As a result, the device efficiency of perovskite solar cells has improved from ~3% up to ~20% in less than a decade. However, the device efficiency of perovskite solar cells still needs to be improved to compete with traditional photovoltaic technologies, such as Silicon and GaAs, and to ultimately realize the theoretically determined Shockley-Queisser efficiency limit.
In this talk, Yoo presents work on further improving the device efficiency by developing a novel interface passivation strategy called selective precursor dissolution (SPD) strategy. The post treatment of the bulk perovskite thin film with 2D perovskites via SPD strategy prevented formation of a detrimental non-perovskite phase at the interface and resulted in much improved thin film quality with reduced detrimental interface recombination. As a result, a certified power conversion efficiency of 22.6% is achieved from a quasi steady-state measurement along with an electroluminescence efficiency up to ~9%. In addition, Yoo discusses the challenges that need to be tackled in order for perovskite solar cells to become a successful photovoltaic technology at a commercial level.
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Nano Explorations is a virtual seminar series powered by MIT.nano that features presentations by MIT students on their work in nanoscience, nanotechnology, and other advanced research fields. The series was launched as a way to keep our nano community connected during the COVID-19 pandemic. Presentations take place on Tuesdays and Thursdays at 11am EST and are open to any interested viewers.
Read more about past and upcoming Nano Explorations at mitnano.mit.edu/nano-explorations.