Perovskite-type superlattices from lead halide perovskite nanocubes

Abstract

For over 80 years, tailored molecular assemblies (e.g., H-and J-aggregates) have been of interest for the emergence of collective phenomena in their optical spectra 1 , coherent long-range energy transport 2,3 and their conceptual similarity with natural light-harvesting complexes 4,5 . Another highly versatile platform for creating controlled, aggregated states exhibiting collective phenomena arises from the organization of colloidal semiconductor nanocrystals (NCs) into long-range ordered superlattices (SLs) 6 . Cesium lead halide perovskite NCs 7-9 have recently emerged as highly appealing building blocks, owing to their high oscillator strength 10 , slow dephasing (long coherence times of up to 80 ps) 11,12 , minimal inhomogeneous broadening of emission lines, and a bright triplet exciton character with orthogonal dipole orientation 10 , potentially enabling an efficient omnidirectional coupling. Here we present perovskite-type (ABO3) binary and ternary NC SLs by a shapedirected co-assembly of steric-stabilized, highly luminescent cuboid-shaped CsPbBr3 NCs (occupying B-and/or O-sites) with spherical Fe3O4 or NaGdF4 NCs (A-sites) and truncated-cuboid PbS NCs (B-site). Such ABO3 SLs, as well as other newly obtained SL structures (binary NaCl-and AlB2-types), exhibit a high degree of orientational ordering of CsPbBr3 nanocubes. These novel perovskite mesostructures exhibit superfluorescence (SF) -a collective emission resulting in a burst of photons. SF is characterized, at high excitation density, by emission pulses with ultrafast (22 ps) radiative decay and Burnham-Chiao ringing behaviour with a strongly accelerated build-up time.

Self-Assembly and Regrowth of Metal Halide Perovskite Nanocrystals for Optoelectronic Applications

“…(d–f) TEM images of binary ABO 3 -type (d), binary NaCl-type (e), and ternary ABO 3 -type (f) superlattices from MHP nanocubes. Reproduced with permission from ref ( 47 ). Copyright 2021 Nature Publishing Group.…”

“… 45 For example, the addition of oleic acid and oleylamine (OAm) can passivate bare NC surfaces, prevent solvent dewetting, and stimulate depletion attraction, thereby assisting in the formation of CsPbBr 3 NC superlattices, 31 where the building blocks (CsPbBr 3 nanocubes) are atomically aligned exclusively via the four vertical {100} c facets 46 (subscript “c” represents cubic crystal structure). The solvent evaporation technique has also been extended to the construction of binary and ternary superlattices via coassembly of cubic CsPbBr 3 NCs and other types of NCs (e.g., Fe 3 O 4 , NaGdF 4 , and PbS), 47 enriching the membership of MHP ensemble families ( Figure 2 d–f).…”

The making of a reconfigurable semiconductor with a soft ionic lattice

“…(I and J) Self-assembly of CsPbBr3 nanocrystals with other nanocrystals to form binary or ternary superlattices with different lattice types. 23 Copyright 2021 Springer Nature.…”

Perspective: multi-dimensional coherent spectroscopy of perovskite nanocrystals

“…For example, photoluminescence-detected MDCS [63] isolates the quantum pathways leading to incoherent luminescence and can inform the mechanisms that limit the performance of light-emitting devices. Photocurrent-detected MDCS [64] could also address many interesting questions concerning transport and other collective phenomena in PNC superlattices [10,65].…”