Rapid Characterization and Parameter Space Exploration of Perovskites Using an Automated Routine

Abstract

Hybrid, e.g., organic inorganic, perovskites from the type methylammonium lead iodide CH 3 NH 3 PbI 3 are promising solar cell materials. However, due to the large parameter space spanned by the manifold combinations of divalent metals with organic cations and anions, an efficient approach is needed to rapidly test and categorize new promising materials. Herein, we developed a high throughput approach for the automated synthesis of perovskite layers with different precursor ratios at varying annealing temperatures. The layers were analyzed by optical absorption and photoluminescence (PL) spectroscopy as well as X-ray diffraction (XRD) and evaluated using two different procedures. The first one is a stepwise exclusion of nonperforming reactant ratios and synthesis conditions by using both spectroscopic techniques, followed by a final validation of the procedure by XRD. In the second procedure, only PL results were consulted in combination with high throughput screening using design of experiments (DoE) to reduce the total number of experiments needed and compared to the manual cascade approach. Noteworthy, by simple PL screening, it was possible to identify the best ratio of perovskite to byproducts and annealing temperature. Thus, only with PL, more detailed results as with the manual protocol were reached, while at the same time the effort for characterization was significantly reduced (by 60% of the experimental time). In conclusion, our approach opens a way toward fast and efficient identification of new promising materials under different reaction and process conditions.

High‐Throughput Robotic Synthesis and Photoluminescence Characterization of Aqueous Multinary Copper–Silver Indium Chalcogenide Quantum Dots

“…In this regard, the best strategies for a high-throughput NC production are associated with robotized synthetic procedures and auto matized characterization protocols allowing human-related uncertainty factors to be excluded. Such methods are currently in a rapid development for other promising materials, such as luminescent binary II-VI QDs [8][9][10][11] and hybrid perovskite microand nanocrystals, [12][13][14][15][16][17][18][19][20] but are still to be realized for multinary metal-chalcogenide NC light absorbers and emitters.…”

Robot-Accelerated Perovskite Investigation and Discovery

“…A total of 8172 ITC reactions were performed in 45 different chemical systems, each of which contains lead(II) iodide and an organic cation. Here, 45 S5, and S6, high-throughput screening allowed for the identification of conditions that result in large crystals (indicated by red circles) for each chemical system, demonstrating the efficacy of exploratory work using this automated workflow. Whereas only methylammonium (MA) and formamidinium (FA) halide perovskites were previously known to form via ITC, 34−36 we find that ITC is possible for perovskites that incorporate organoammonium cations with a much wider range of molecular weights, degree of ammonium substitution, and structural features such as aliphatic and aromatic rings.…”

“…High-throughput synthetic approaches are well-suited for efficiently exploring large experimental parameter spaces . Such approaches have been used to search for new organic reactions, − optimize synthetic conditions of inorganic materials, − and discover new inorganic materials for energy, catalysis, and sensing applications. − Specifically, high-throughput synthetic approaches have been used to explore the formation of metal halide perovskites in the form of thin-films, , polycrystalline samples, nanocrystals, , and, recently, as single crystals produced by antisolvent vapor-assisted crystallization . The application of such high-throughput approaches to the growth of metal halide perovskite single crystals requires the adaptation of experimental routes to ensure compatibility with liquid handling robotics.…”

High-Throughput Synthesis of Thin Films for the Discovery of Energy Materials: A Perspective

“…Spin-coating implies depositing films from many solutions premade by discrete mixing of precursors, also termed fragmentary (or discontinuous) composition optimization (Figure , left panel). Since the fragmentary approach is discontinuous and, hence, misses intermediate compositions, computational tools are usually used to simulate the entire parameter space …”