Pick a Color MARIA: Adaptive Sampling Enables the Rapid Identification of Complex Perovskite Nanocrystal Compositions with Defined Emission Characteristics.

Recent advances in the development of hybrid organic-inorganic lead halide perovskite (LHP) nanocrystals (NCs) have demonstrated their versatility and potential application in photovoltaics and as light sources through compositional tuning of optical properties. That said, due to their compositional complexity, the targeted synthesis of mixed-cation and/or mixed-halide LHP NCs still represents an immense challenge for traditional batch-scale chemistry. To address this limitation, we herein report the integration of a high-throughput segmented-flow microfluidic reactor and a self-optimizing algorithm for the synthesis of NCs with defined emission properties. The algorithm, named Multiparametric Automated Regression Kriging Interpolation and Adaptive Sampling (MARIA), iteratively computes optimal sampling points at each stage of an experimental sequence to reach a target emission peak wavelength based on spectroscopic measurements. We demonstrate the efficacy of the method through the synthesis of multinary LHP NCs, (Cs/FA)Pb(I/Br)3 (FA = formamidinium) and (Rb/Cs/FA)Pb(I/Br)3 NCs, using MARIA to rapidly identify reagent concentrations that yield user-defined photoluminescence peak wavelengths in the green-red spectral region. The procedure returns a robust model around a target output in far fewer measurements than systematic screening of parametric space and additionally enables the prediction of other spectral properties, such as, full-width at half-maximum and intensity, for conditions yielding NCs with similar emission peak wavelength.

[1]  G. Matheron Principles of geostatistics , 1963 .

[2]  Donald R. Jones,et al.  Efficient Global Optimization of Expensive Black-Box Functions , 1998, J. Glob. Optim..

[3]  Timothy W. Simpson,et al.  Metamodels for Computer-based Engineering Design: Survey and recommendations , 2001, Engineering with Computers.

[4]  Donald R. Jones,et al.  A Taxonomy of Global Optimization Methods Based on Response Surfaces , 2001, J. Glob. Optim..

[5]  Andrew J deMello,et al.  Microfluidic routes to the controlled production of nanoparticles. , 2002, Chemical communications.

[6]  Thomas J. Santner,et al.  Design and analysis of computer experiments , 1998 .

[7]  V. M. Goldschmidt,et al.  Die Gesetze der Krystallochemie , 1926, Naturwissenschaften.

[8]  A. Forrester,et al.  Design and analysis of 'noisy' computer experiments , 2006 .

[9]  A. deMello,et al.  Intelligent routes to the controlled synthesis of nanoparticles. , 2007, Lab on a chip.

[10]  Andy J. Keane,et al.  Recent advances in surrogate-based optimization , 2009 .

[11]  Tsutomu Miyasaka,et al.  Organometal halide perovskites as visible-light sensitizers for photovoltaic cells. , 2009, Journal of the American Chemical Society.

[12]  Jonathan P. McMullen,et al.  An Automated Microfluidic System for Online Optimization in Chemical Synthesis , 2010 .

[13]  Gang Han,et al.  Reproducible, high-throughput synthesis of colloidal nanocrystals for optimization in multidimensional parameter space. , 2010, Nano letters.

[14]  Nam-Gyu Park,et al.  6.5% efficient perovskite quantum-dot-sensitized solar cell. , 2011, Nanoscale.

[15]  Klavs F. Jensen,et al.  Automated Multitrajectory Method for Reaction Optimization in a Microfluidic System using Online IR Analysis , 2012 .

[16]  John C. deMello,et al.  Segmented Flow Reactors for Nanocrystal Synthesis , 2013, Advanced materials.

[17]  Andrew J. deMello,et al.  Fast and Reliable Metamodeling of Complex Reaction Spaces Using Universal Kriging , 2014 .

[18]  F. Giustino,et al.  Steric engineering of metal-halide perovskites with tunable optical band gaps , 2014, Nature Communications.

[19]  Anthony K. Cheetham,et al.  Solid-state principles applied to organic–inorganic perovskites: new tricks for an old dog , 2014 .

[20]  Richard M Maceiczyk,et al.  Nanocrystal synthesis in microfluidic reactors: where next? , 2014, Lab on a chip.

[21]  Olga Malinkiewicz,et al.  Nontemplate synthesis of CH3NH3PbBr3 perovskite nanoparticles. , 2014, Journal of the American Chemical Society.

[22]  Andrew J. deMello,et al.  Online detection and automation methods in microfluidic nanomaterial synthesis , 2015 .

[23]  Christopher H. Hendon,et al.  Nanocrystals of Cesium Lead Halide Perovskites (CsPbX3, X = Cl, Br, and I): Novel Optoelectronic Materials Showing Bright Emission with Wide Color Gamut , 2015, Nano letters.

[24]  M. Fiebig,et al.  Low-threshold amplified spontaneous emission and lasing from colloidal nanocrystals of caesium lead halide perovskites , 2015, Nature Communications.

[25]  H. Zeng,et al.  All‐Inorganic Colloidal Perovskite Quantum Dots: A New Class of Lasing Materials with Favorable Characteristics , 2015, Advanced materials.

[26]  Abhishek Swarnkar,et al.  Colloidal CsPbBr3 Perovskite Nanocrystals: Luminescence beyond Traditional Quantum Dots. , 2015, Angewandte Chemie.

[27]  Manas R. Parida,et al.  Air-Stable Surface-Passivated Perovskite Quantum Dots for Ultra-Robust, Single- and Two-Photon-Induced Amplified Spontaneous Emission. , 2015, The journal of physical chemistry letters.

[28]  Chang Su Shim,et al.  Highly stable and efficient solid-state solar cells based on methylammonium lead bromide (CH3NH3PbBr3) perovskite quantum dots , 2015 .

[29]  Shaojun Guo,et al.  Room Temperature Single-Photon Emission from Individual Perovskite Quantum Dots. , 2015, ACS nano.

[30]  Ashley R. Marshall,et al.  Quantum dot–induced phase stabilization of α-CsPbI3 perovskite for high-efficiency photovoltaics , 2016, Science.

[31]  Yitong Dong,et al.  Exciton-to-Dopant Energy Transfer in Mn-Doped Cesium Lead Halide Perovskite Nanocrystals. , 2016, Nano letters.

[32]  Min-Sang Lee,et al.  All-inorganic cesium lead halide perovskite nanocrystals for photodetector applications. , 2016, Chemical communications.

[33]  Jasmina A. Sichert,et al.  Colloidal lead halide perovskite nanocrystals: synthesis, optical properties and applications , 2016 .

[34]  J. Berry,et al.  Stabilizing Perovskite Structures by Tuning Tolerance Factor: Formation of Formamidinium and Cesium Lead Iodide Solid-State Alloys , 2016 .

[35]  Richard M Maceiczyk,et al.  Kinetics of nanocrystal synthesis in a microfluidic reactor: theory and experiment , 2016 .

[36]  Anders Hagfeldt,et al.  Incorporation of rubidium cations into perovskite solar cells improves photovoltaic performance , 2016, Science.

[37]  Antonietta Guagliardi,et al.  Monodisperse Formamidinium Lead Bromide Nanocrystals with Bright and Stable Green Photoluminescence , 2016, Journal of the American Chemical Society.

[38]  Andrew J. deMello,et al.  Synthesis of Cesium Lead Halide Perovskite Nanocrystals in a Droplet-Based Microfluidic Platform: Fast Parametric Space Mapping. , 2016, Nano letters.

[39]  Anders Hagfeldt,et al.  Cesium-containing triple cation perovskite solar cells: improved stability, reproducibility and high efficiency† †Electronic supplementary information (ESI) available. See DOI: 10.1039/c5ee03874j Click here for additional data file. , 2016, Energy & environmental science.

[40]  Klavs F Jensen,et al.  Feedback in Flow for Accelerated Reaction Development. , 2016, Accounts of chemical research.

[41]  J. Pérez‐Prieto,et al.  The Luminescence of CH3 NH3 PbBr3 Perovskite Nanoparticles Crests the Summit and Their Photostability under Wet Conditions is Enhanced. , 2016, Small.

[42]  H. Zeng,et al.  Nonlinear Absorption and Low-Threshold Multiphoton Pumped Stimulated Emission from All-Inorganic Perovskite Nanocrystals. , 2016, Nano letters.

[43]  Haibo Zeng,et al.  Quantum Dot Light‐Emitting Diodes Based on Inorganic Perovskite Cesium Lead Halides (CsPbX3). , 2016 .

[44]  R. Palgrave,et al.  On the application of the tolerance factor to inorganic and hybrid halide perovskites: a revised system , 2016, Chemical science.

[45]  H. Zeng,et al.  CsPbX3 Quantum Dots for Lighting and Displays: Room‐Temperature Synthesis, Photoluminescence Superiorities, Underlying Origins and White Light‐Emitting Diodes , 2016 .

[46]  Aifei Wang,et al.  Ligand-Mediated Synthesis of Shape-Controlled Cesium Lead Halide Perovskite Nanocrystals via Reprecipitation Process at Room Temperature. , 2016, ACS nano.

[47]  Manas R. Parida,et al.  Engineering Interfacial Charge Transfer in CsPbBr3 Perovskite Nanocrystals by Heterovalent Doping. , 2017, Journal of the American Chemical Society.

[48]  M. Grätzel,et al.  Phase Segregation in Cs-, Rb- and K-Doped Mixed-Cation (MA)x(FA)1–xPbI3 Hybrid Perovskites from Solid-State NMR , 2017, Journal of the American Chemical Society.

[49]  Phillip Lee,et al.  Inorganic Rubidium Cation as an Enhancer for Photovoltaic Performance and Moisture Stability of HC(NH2)2PbI3 Perovskite Solar Cells , 2017 .

[50]  M. Grätzel,et al.  Chemical Distribution of Multiple Cation (Rb+, Cs+, MA+, and FA+) Perovskite Materials by Photoelectron Spectroscopy , 2017 .

[51]  Richard M Maceiczyk,et al.  Small but Perfectly Formed? Successes, Challenges, and Opportunities for Microfluidics in the Chemical and Biological Sciences , 2017 .

[52]  S. Dutta,et al.  Doping Mn2+ in Lead Halide Perovskite Nanocrystals: Successes and Challenges , 2017 .

[53]  Kai Dadhe,et al.  Real‐Time Optimization in the Chemical Processing Industry , 2017 .

[54]  U. Rothlisberger,et al.  Stabilization of the Perovskite Phase of Formamidinium Lead Triiodide by Methylammonium, Cs, and/or Rb Doping. , 2017, The journal of physical chemistry letters.

[55]  Maksym V. Kovalenko,et al.  Properties and potential optoelectronic applications of lead halide perovskite nanocrystals , 2017, Science.

[56]  Antonietta Guagliardi,et al.  Dismantling the “Red Wall” of Colloidal Perovskites: Highly Luminescent Formamidinium and Formamidinium–Cesium Lead Iodide Nanocrystals , 2017, ACS nano.

[57]  He Huang,et al.  Lead Halide Perovskite Nanocrystals in the Research Spotlight: Stability and Defect Tolerance , 2017, ACS energy letters.

[58]  Richard M Maceiczyk,et al.  Microfluidic Technology: Uncovering the Mechanisms of Nanocrystal Nucleation and Growth. , 2017, Accounts of chemical research.

[59]  Andrew J. deMello,et al.  Microfluidic Reactors Provide Preparative and Mechanistic Insights into the Synthesis of Formamidinium Lead Halide Perovskite Nanocrystals , 2017 .

[60]  Sara Bals,et al.  Highly Emissive Divalent-Ion-Doped Colloidal CsPb1–xMxBr3 Perovskite Nanocrystals through Cation Exchange , 2017, Journal of the American Chemical Society.

[61]  Connor W. Coley,et al.  Automated microfluidic platform for systematic studies of colloidal perovskite nanocrystals: towards continuous nano-manufacturing. , 2017, Lab on a chip.

[62]  Florian Hoegl,et al.  Brightly Luminescent and Color-Tunable Formamidinium Lead Halide Perovskite FAPbX3 (X = Cl, Br, I) Colloidal Nanocrystals. , 2017, Nano letters.

[63]  Hao Zhang,et al.  CsPb x Mn 1 − x Cl 3 Perovskite Quantum Dots with High Mn Substitution Ratio , 2017 .

[64]  Hybrid Perovskite Light-Emitting Diodes Based on Perovskite Nanocrystals with Organic-Inorganic Mixed Cations. , 2017, Advanced materials.

[65]  Chen Wu,et al.  Highly Luminescent and Stable Perovskite Nanocrystals with Octylphosphonic Acid as a Ligand for Efficient Light-Emitting Diodes. , 2018, ACS applied materials & interfaces.

[66]  Richard M. Maceiczyk,et al.  Unveiling the Shape Evolution and Halide-Ion-Segregation in Blue-Emitting Formamidinium Lead Halide Perovskite Nanocrystals Using an Automated Microfluidic Platform. , 2018, Nano letters.

[67]  Chih-Jen Shih,et al.  Colloidal CsPbX3 (X = Cl, Br, I) Nanocrystals 2.0: Zwitterionic Capping Ligands for Improved Durability and Stability , 2018, ACS energy letters.