Multicomponent Nanocrystal Superlattices Comprising Lead Halide Perovskite Nanocubes

Abstract

Cesium lead halide perovskite nanocrystals (NCs), owing to their outstanding optoelectronic properties (high oscillator strength of bright triplet excitons, slow dephasing, minimal inhomogeneous broadening of emission lines), are promising materials for creating coherent macroscopic states that can be utilized in quantum applications. Perovskite NCs self-assembled into ordered superlattices (SLs) with simple cubic packing of cubic NCs have been shown to emit ultrafast (ca. 20 ps) superfluorescent light. Further advancement in the field, required for programmable tuning of the collective emission and for building a theoretical framework, relies on the higher-level, exquisite structural engineering of the perovskite NC structures, wherein the use of additional building blocks may allow control over the mutual arrangement and orientation of perovskite nanocubes. We present a wide structural diversity in multicomponent, long-range ordered SLs obtained by shape-directed co-assembly of cubic CsPbBr3 NCs with the spherical, truncated cuboid, and disk-shaped NCs. When combined with spherical Fe3O4 or NaGdF4 NCs, SLs of five structure types form, namely, NaCl-, AlB2-, and novel, uncommon to all-sphere assemblies AB2- as well as quasi-ternary ABO3- and ABO6-types with cubes occupying B- and O-sites. Targeted incorporation of truncated cuboid PbS NCs on B-sites results in the formation of ternary ABO3-type SLs. We then demonstrate the effect of superlattice structure on the collective optical properties. Combining perovskite nanocubes with other shape-anisotropic building blocks extends the library of accessible SL structures. With truncated cuboid PbS NCs as a larger component, in addition to binary NaCl-, AlB2- and ABO3-type SLs, CuAu-type SL was obtained. Co-assembly of CsPbBr3 nanocubes with larger disk-shaped LaF3 NCs results in the formation of six columnar structures with AB, AB2, AB4, and AB6 stoichiometry. In the systems with comparable dimensions of nanocubes (8.6 nm) and nanodisks (6.5–12.5 nm), other, non-columnar structures are observed, such as ReO3-type SL, featuring intimate intermixing and face-to-face alignment of disks and cubes. With large and thick NaGdF4 nanodisks the orthorhombic SL resembling CaC2 structure with clusters of CsPbBr3 NCs was obtained. In the above-mentioned structures, 8.6 nm perovskite nanocubes exhibit a high degree of orientational ordering. We also explore the substrate-free assembly methods that allow obtaining binary supraparticles and free-floating SL films comprising perovskite nanocrystals. [1] Cherniukh, I.; Rainò, G.; Stöferle, T.; Burian, M.; Travesset, A.; Naumenko, D.; Amenitsch, H.; Erni, R.; Mahrt, R. F.; Bodnarchuk, M. I.; Kovalenko, M. V. Perovskite-Type Superlattices from Lead Halide Perovskite Nanocubes. Nature 2021, 593, 535– 542. [2] Cherniukh, I.; Raino, G.; Sekh, T. V.; Zhu, C.; Shynkarenko, Y.; John, R. A.; Kobiyama, E.; Mahrt, R. F.; Stöferle, T.; Erni, R.; Kovalenko, M. V.; Bodnarchuk, M. I. Shape-Directed Co-Assembly of Lead Halide Perovskite Nanocubes with Dielectric Nanodisks into Binary Nanocrystal Superlattices. ACS Nano 2021, 15, 16488-16500. [3] Cherniukh, I; Sekh, T. V.; Rainò, G.; Ashton, O. J.; Burian, M.; Travesset, A.; Athanasiou, M.; Manoli, A.; John, R. A.; Svyrydenko, M.; Morad, V.; Shynkarenko, Y.; Montanarella, F.; Naumenko, D.; Amenitsch, H.; Itskos, G.; Mahrt, R. F.; Stöferle, T.; Erni, R.; Kovalenko, M. V.; Bodnarchuk, M. I. Structural Diversity in Multicomponent Nanocrystal Superlattices Comprising Lead Halide Perovskite Nanocubes. ACS Nano 2022, 16, 5, 7210–7232