Abstract

Halide perovskite nanocrystals are prepared via several synthetic routes to obtain dimension-controlled nanocubes, nanoplatelets or nanowires. We investigate the effect of size and dimensionality on the optical and electronic properties of the nanocrystals, focusing on quantum-confinement and carrier dynamics. With binding energies of up to 300 meV, 2D nanoplatelets exhibit many properties reminiscent of epitaxially grown quantum wells but at room temperature. However, due to their unique geometry and organic ligand surrounding, they exhibit vastly different carrier relaxation dynamics, with a strong dependence on the thickness of the samples. These nanoplatelets are shown to be excellent emitters in the blue spectral region, where perovskite nanocrystals typically perform poorly. Inorganic Cs-based nanocubes, which have previously displayed extremely high quantum yields, are used as precursors to create larger structures. We explore the energetic and electronic coupling between the NCs and explore the resulting optical properties, especially for light harvesting and light emitting applications.