Combinatorial Synthesis and Screening of Mixed Halide Perovskite Megalibraries

Abstract

A significant bottleneck in the discovery of new mixed halide perovskite (MHP) compositions and structures is the time-consuming and low-throughput nature of current synthesis and screening methods. Here, a high-throughput strategy is presented that can be used to synthesize combinatorial libraries of MHPs with deliberate control over the halide mixing ratio and particle size (for example, CsPb­(Br1–x Cl x )3 (0 < x < 1) with sizes between ∼100 and 400 nm). This strategy combines evaporation–crystallization polymer pen lithography (EC-PPL) and defect-engineered anion exchange to spatially encode particle size and composition, respectively. Laser exposure is used to selectively modify the defect concentration of individual particles, and thus the degree of subsequent anion exchange, allowing the preparation for ultra-high-density arrays of distinct compositions (>1 unique particle/μm2). This method was utilized to rapidly generate a library of ∼4000 CsPb­(Br1–x Cl x )3 particles that was then screened for high-efficiency blue photoemission, which yielded CsPb­(Br0.6Cl0.4)3 as the composition with the highest photoluminescence intensity. The combinatorial synthesis and screening strategy provided here, and the mechanistic understanding of the defect-engineering process gleaned from it, will enable the rapid discovery of exceptional MHP optoelectronic materials.

Molecular Thin Films Enable the Synthesis and Screening of Nanoparticle Megalibraries Containing Millions of Catalysts

“…Discovery of a New Photodegradation Catalyst. Our group is now using this megalibrary synthesis strategy to explore a breadth of materials applications, including electrocatalysis, luminescence, 7 and durability. Here, we illustrate the power of megalibraries for ultrafast materials discovery by combining nanoparticle composition gradients with the above method for rapid visualization of catalytic activity via degradation of organic pollutants.…”

“…Patterns consisting of up to 5 billion identical nanomaterials have been synthesized, 42 showing large area parallel synthesis is highly controllable. In addition, we and others have reported megalibraries consisting of gradients of either Au−Cu nanoparticles or mixed halide perovskites, which has led to the discovery of a new catalyst for single-walled carbon nanotube synthesis 3 and a blue-emitting halide perovskite with recording-breaking photoluminescence intensity, 7 respectively. However, the strict requirements for substrate chemistry (e.g., atomically flat and typically chemically modified Si-based substrates to ensure clean reactor deposition and particle formation) in addition to low-throughput compositional tuning and screening capabilities have thus far limited libraries to 10 2 − 10 3 unique nanomaterials.…”

“…Materials discovery drives technological advancement, yet is slowed by two fundamental challenges: synthesis and characterization. One approach to accelerating discovery is using combinatorial libraries and high-throughput experimentation (HTE), as demonstrated by research on sustainable energy catalysis, − luminescence, , photovoltaics, molecular synthesis, , and pharmaceuticals. , To prepare such libraries, materials must be either isolated in wells ,, or precisely patterned on substrates ,,, to distinguish differing properties. In doing so, the substrate chemistry and dimensions must be considered since material–substrate interactions are critical for certain functions such as electron transfer, plasmonics, or catalysis .…”

“…Materials discovery drives technological advancement, yet is slowed by two fundamental challenges: synthesis and characterization. One approach to accelerating discovery is using combinatorial libraries and high-throughput experimentation (HTE), as demonstrated by research on sustainable energy catalysis, 1−5 luminescence, 6,7 photovoltaics, 8 molecular synthesis, 9,10 and pharmaceuticals. 11,12 To prepare such libraries, materials must be either isolated in wells 9,12,13 or precisely patterned on substrates 3,4,6,7 to distinguish differing properties.…”

Elucidating Structure Formation in Highly Oriented Triple Cation Perovskite Films

“…Metal halide perovskites are a remarkable class of semiconductors whose excellent optoelectronic properties make them particularly promising for application in photovoltaics. [1,2] Over the DOI: 10.1002/advs.202206325 last decade, significant advances have been made in the design of their composition, [3] passivation of defects, [4] interfacial engineering, [5] and control over the layer's microstructure. [6] The latter has been shown to be highly important, since the microstructure of the perovskite active layer has a significant effect not only on the optoelectronic properties and device efficiency, [7] but also on the stability of perovskite solar cells.…”