8:00 PM - EN08.13.30
Metal Encapsulation of Scalable Perovskite Devices for Operation Under High-Moisture Environments
Virgil Andrei1,Robert Hoye1,Shahab Ahmad1,Michael De Volder1,Richard Friend1,Erwin Reisner1
University of Cambridge1
Research in perovskite photovoltaics (PV) has witnessed a tremendous development over the last decade, as leaps in efficiency and stability were achieved by improvements in the device architecture. Progress in the charge selective layers led to better charge collection and band alignment, whereas development of multiple cation mixed halide perovskite phases resulted in robustness beyond 500 h under harsh environmental conditions.[1,2] Yet, the broad commercialization of perovskite PV panels has remained an elusive goal, as issues remain regarding the modules’ scalability and their long-term moisture- and air-sensitivity.
While typical stability tests employ high ambient humidity and elevated temperatures to accelerate device degradation, it must be pointed out that real-life module operation involves device soaking, mechanical stress and temperature changes, as experienced by a solar panel under say a heavy rain. Accordingly, the investigation of device robustness when submerged in aqueous, potentially corrosive electrolyte solutions may provide a more realistic benchmark for evaluating encapsulation strategies.
In this contribution, we introduce photoelectrochemical (PEC) device testing as a way to evaluate encapsulation methods, which are employed for perovskite PV devices of different sizes. Accordingly, we will focus on the recent advances in solar cell encapsulation achieved using a thin layer of Field’s metal (FM), a low melting InBiSn alloy.[3,4,5] The metal layer has a dual function, as protective barrier and electrical contact, which can act as an electronic interface to a surface-bound catalyst for PEC applications. In particular, the FM encapsulation demonstrates an advantage for the J-V characterization of larger single pixel perovskite solar cells, which can be straightforwardly employed as hydrogen-evolving photocathodes after electroless deposition of a platinum nanoparticle catalyst. In this respect, we will also place special focus on the scalability of FM encapsulated solar cells, highlighting the interplay between device performance and serial resistance losses for single pixel perovskite PV devices of sizes of up to 10 cm2.
In this context of photoelectrochemical benchmarking, we will also give a brief introduction to the basic principles of solar-fuel research and its advantages in terms of simultaneous energy production and storage, showcasing our recent progress in the development of perovskite-BiVO4 PEC tandem devices for unassisted water splitting. Taking our current progress on 300 cm2 large scale BiVO4 panels into account, we envision rooftop PEC devices by combining the BiVO4 photoanodes with perovskite photocathodes of matching sizes. In the context of commercial applications, we will further address the potential of lowering down the overall device costs by appropriate choice of components.
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