Using automated serendipity to discover how trace water promotes and inhibits lead halide perovskite crystal formation
Abstract
Halide perovskite materials have attracted great interest for applications in low-cost, solution-processed solar cells and other optoelectronics applications. The role of moisture in perovskite device degradation and crystal formation processes remains poorly understood. Here, we use a data-driven approach to discover the influence of trace amounts of water on perovskite crystal formation by analyzing a comprehensive dataset of 8470 inverse-temperature crystallization lead iodide perovskite synthesis reactions, performed over 20 months using a robotic system. We identified discrepancies between the empirical crystal formation rates in batches of experiments conducted under different ambient relative humidity conditions for each organoammonium cation. We prioritized these using a statistical model and then used the robotic system to conduct 1296 controlled interventional experiments, in which small amounts of water were deliberately introduced to the reactions. The addition of trace amounts of water promotes crystal formation for 4-methoxyphenylammonium lead iodide and iso-propylammonium lead iodide and inhibits crystal formation for dimethylammonium lead iodide and acetamidinium lead iodide. We also performed thin-film syntheses of these four materials and determined the grain size distributions using scanning electron microscopy. The addition of water results in smaller grain sizes for dimethylammonium and larger grain sizes for iso-propylammonium, consistent with earlier or delayed nucleation, respectively. The agreement between the inverse temperature crystallization and thin film results indicates that this is a feature of the organoammonium-water interaction that persists despite differences in the synthesis method.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Jul 26, 2021
- Source ID
- 10.1063/5.0059767
Entities
People
- Alexander J. Norquist
- Emory M Chan
- Janak Thapa
- Joshua Schrier
- Mansoor Ani Najeeb Nellikkal
- Noor Titan Putri Hartono
- Philip W. Nega
- Shijing Sun
- Tonio Buonassisi
- Victor Ghosh
- Zhi Li
Organizations
- Defense Advanced Research Projects Agency
- Fordham University
- Haverford College
- Lawrence Berkeley National Laboratory
- Massachusetts Institute of Technology
- National Science Foundation
- Office of Basic Energy Sciences
- The Bronx High School of Science
- The Camille and Henry Dreyfus Foundation