Abstract

Halide perovskites are at the forefront of material’s research with their wide range of applications from light emitting diodes (LEDs) to cheaper perovskite solar cells (PSCs). Solar to power conversion efficiency of PSCs is now >25% [1,2] and perovskite-silicon tandem reaching ~33%[1] even exceeding GaAs. Control over morphological evolution is the key for the superior performances and long-term stability. I perform molecular simulations to understand [1,2,3,4] and predict [5] the phase transitions in halide perovskite, thereby helping and guiding experimental methodologies. Over the last decade to now, almost 20000 papers published on halide perovskites, however this field suffer from reproducibility and lack of fundamental understanding of material properties and synthesis process as experimental efforts have been based on trial-and-error efforts to obtain higher efficiencies. In this talk, first I will discuss key fundamental problems of this field which are beyond the reach of state-of-the-art experimental techniques. Second, I will show how molecular simulations can play a key role to solve the main problems and help experimentalists for industrialization of a high-efficiency perovskite solar cell.

[1] https://www.nrel.gov/pv/interactive-cell-efficiency.html [2] Jeong, Jaeki, Minjin Kim, Jongdeuk Seo, Haizhou Lu, Paramvir Ahlawat, et al. “Pseudo-halide anion engineering for α-FAPbI3 perovskite solar cells.” Nature 592, (2021). [3] Lu, Haizhou, Yuhang Liu, Paramvir Ahlawat, et al. “Vapor-assisted deposition of highly efficient, stable black-phase FAPbI3 perovskite solar cells.” Science 370, (2020). [4] Paramvir Ahlawat,et al. “Atomistic mechanism of the nucleation of methylammonium lead iodide perovskite from solution.” Chemistry of Materials 32, (2019). [5] Paramvir Ahlawat, et al. “A combined molecular dynamics and experimental study of two-step process enabling low-temperature formation of phase-pure α-FAPbI3.” Science Advances 7.17 (2021).