The Anisotropic Complex Dielectric Function of CsPbBr Perovskite Nanorods Obtained via an Iterative Matrix Inversion Method.

Colloidal lead halide perovskite nanorods have recently emerged as promising optoelectronic materials. However, more information about how shape anisotropy impacts their complex dielectric function is required to aid the development of applications that take advantage of the strongly polarized absorption and emission. Here, we have determined the anisotropy of the complex dielectric function of CsPbBr nanorods by analyzing the ensemble absorption spectra in conjunction with the ensemble spectral fluorescence anisotropy.

Kinetic Control for Continuously Tunable Lattice Parameters, Size, and Composition during CsPbX (X = Cl, Br, I) Nanorod Synthesis.

The fast kinetics of all-inorganic CsPbX (X = Cl, Br, or I) nanocrystal growth entail that many synthetic strategies for structural control established in other semiconductor systems do not apply. Rather, products are often determined by thermodynamic factors, limiting the range of synthetic outcomes and functionality. In this study, we show how reaction kinetics are significantly slowed if nanocrystals are prepared using a dual injection strategy that moderates the crucial interaction between cesium and halide during nucleation and growth.

The role of gold oxidation state in the synthesis of Au-CsPbX heterostructure or lead-free CsAuAuX perovskite nanoparticles.

Here, we report that the oxidation state of gold plays a dominant role in determining the reaction products when gold halide salts are mixed with all-inorganic lead halide perovskite nanocrystals. When CsPbX nanocrystals react with Au(i) halide salts, Au nanoparticles are deposited on the surface of the perovskites through the reduction of Au ions by the surfactant ligand shell, to produce Au-CsPbX heterostructures. These heterostructures preserve comparably high photoluminescence quantum yield (PLQY) and show identical XRD diffractograms as the parent CsPbX nanocrystals.