The high demand for energy consumption in everyday life, and fears of climate change are driving the scientific community to explore prospective materials for efficient energy conversion and storage. Perovskites, a prominent category of materials, including metal halides and perovskite oxides have a significant role as energy materials, and can effectively replace conventional materials. The simultaneous need for new energy materials together with the increased interest for making new devices, and exploring new physics, thrust the research to control the structuring of the perovskite materials at the nanoscale. Nanostructuring of the perovskites offers unique features such as a large surface area, extensive porous structures, controlled transport and charge‐carrier mobility, strong absorption and photoluminescence, and confinement effects. These features together with the unique tunability in their composition, shape, and functionalities make perovskite nanocrystals efficient for energy‐related applications such as photovoltaics, catalysts, thermoelectrics, batteries, supercapacitor and hydrogen storage systems. The synthesis procedures of perovskite nanostructures in different morphologies is summarized and the energy‐related properties and applications are extensively discussed in this paper.

Controlled assembly of single-crystal, colloidal maghemite nanoparticles is facilitated via a high-temperature polyol-based pathway. Structural characterization shows that size-tunable nanoclusters of 50 and 86 nm diameters (D), with high dispersibility in aqueous media, are composed of ∼13 nm (d) crystallographically oriented nanoparticles. The interaction effects are examined against the increasing volume fraction, φ, of the inorganic magnetic phase that goes from individual colloidal nanoparticles (φ = 0.47) to clusters (φ = 0.72). The frozen-liquid dispersions of the latter exhibit weak ferrimagnetic behaviour at 300 K. Comparative Mössbauer spectroscopic studies imply that intra-cluster interactions come into play. New insight emerges from the clusters' temperature-dependent ac susceptibility that displays two maxima in χ′′(T), with strong frequency dispersion. Scaling-law analysis together with the observed memory effects suggests that a superspin-glass state settles-in at T_B ∼ 160–200 K, while at lower-temperatures, surface spin-glass freezing is established at T_f ∼ 40–70 K. In such nanoparticle-assembled systems, with increased φ, Monte Carlo simulations corroborate the role of the inter-particle dipolar interactions and that of the constituent nanoparticles' surface spin disorder in the emerging spin-glass dynamics.

Ultra-thin and highly uniform CsPbBr₃ nanowires over micron-size lengths and widths down to the quantum confinement regime have been fabricated via a facile, low-temperature precipitation-based method. This synthesis approach is the first of its kind that is carried out on the work-bench. The nanowires’ photoluminescence is shown to improve over time.

Ligand-free all-inorganic lead halide nanocubes have been investigated as ozone sensing materials operating at room temperature. It is found that the nanocubes, crystallined in the orthorhombic CsPbBr₃ structure, can operate at room temperature, be self-powered and exhibit high sensitivity and remarkable repeatability. More importantly, they demonstrate higher sensitivity (54% in 187 ppb) and faster response and recovery times compared to hybrid lead mixed halide perovskite (CH₃NH₃PbI_3−xCl_x) layers, which is the only lead halide perovskite material tested for ozone sensing, to date. Following the exposure to an ozone environment, the stoichiometry and the morphology of the nanocubes remain unaltered. The facile and easy fabrication process together with the high responsivity and stability to the ozone environment makes the bare CsPbBr₃ nanocubes a promising material for sensing applications. The sensing properties of the nanoparticulate metal halides presented here provide new exciting opportunities towards engineering reliable and cheap sensing elements for room-temperature operated and self-powered sensors.

A simple and low temperature post-glass quenching encapsulation method for the formation of highly luminescent and ultrastable perovskite patterns within phosphate glass.