Highly Photoluminescent CsPbBr3/CsPb2Br5 NCs@TEOS Nanocomposite in Light-Emitting Diodes

Correlative Imaging of Individual CsPbBr3 Nanocrystals: Role of Isolated Grains in Photoluminescence of Perovskite Polycrystalline Thin Films

We report on the optical properties of a CsPbBr₃ polycrystalline thin film on a single grain level. A sample composed of isolated nanocrystals (NCs) mimicking the properties of the polycrystalline thin film grains that can be individually probed by photoluminescence spectroscopy was prepared. These NCs were analyzed using correlative microscopy allowing the examination of structural, chemical, and optical properties from identical sites. Our results show that the stoichiometry of the CsPbBr₃ NCs is uniform and independent of the NCs' morphology. The photoluminescence (PL) peak emission wavelength is slightly dependent on the dimensions of NCs, with a blue shift up to 9 nm for the smallest analyzed NCs. The magnitude of the blueshift is smaller than the emission line width, thus detectable only by high-resolution PL mapping. By comparing the emission energies obtained from the experiment and a rigorous effective mass model, we can fully attribute the observed variations to the size-dependent quantum confinement effect.

Aromatic Amino Acid-Mediated Perovskite Nanocrystals: Fluorescence Tuning and Morphological Evolution

Lead halide perovskites with high fluorescent and tunable morphology appeared at the forefront of materials chemistry because of their corresponding impressive optoelectronic properties. The current advancement of metal halide perovskites put forward the functional and bidentate ligand to expand their utilization in modified ligand chemistry. We successfully introduced nontoxic aromatic amino acid as a capping ligand to synthesize the perovskite nanocrystals (PNCs). The implementation of aromatic amino acid for the construction of CsPbX₃ nanocrystals (NCs) provides the synergetic service of the carboxylic and amine groups with the phenyl residue, which prompts the formation of NCs with high fluorescence intensity. The experimental results demonstrate the emissive property of PNCs in a whole visible region with long-term stability. Additionally, the morphology of the NCs has been tuned. We performed several characterization techniques to investigate the nature of the NCs in the solid and solution phases.

Nanostructured perovskites for nonvolatile memory devices

Perovskite materials have driven tremendous advances in constructing electronic devices owing to their low cost, facile synthesis, outstanding electric and optoelectronic properties, flexible dimensionality engineering, and so on. Particularly, emerging nonvolatile memory devices (eNVMs) based on perovskites give birth to numerous traditional paradigm terminators in the fields of storage and computation. Despite significant exploration efforts being devoted to perovskite-based high-density storage and neuromorphic electronic devices, research studies on materials' dimensionality that has dominant effects on perovskite electronics' performances are paid little attention; therefore, a review from the point of view of structural morphologies of perovskites is essential for constructing perovskite-based devices. Here, recent advances of perovskite-based eNVMs (memristors and field-effect-transistors) are reviewed in terms of the dimensionality of perovskite materials and their potentialities in storage or neuromorphic computing. The corresponding material preparation methods, device structures, working mechanisms, and unique features are showcased and evaluated in detail. Furthermore, a broad spectrum of advanced technologies (e.g., hardware-based neural networks, in-sensor computing, logic operation, physical unclonable functions, and true random number generator), which are successfully achieved for perovskite-based electronics, are investigated. It is obvious that this review will provide benchmarks for designing high-quality perovskite-based electronics for application in storage, neuromorphic computing, artificial intelligence, information security, etc.