A simple yet general swelling-deswelling microencapsulation strategy has been developed to achieve well dispersed and intimately passivated crystalline organic-inorganic perovskites nanoparticles within polymer matrixes and results in a series of highly luminescent CH NH PbBr (MAPbBr )-polymer composite films with unprecedented water and thermal stabilities and superior color purity.

Organic-inorganic halide perovskite quantum dots (PQDs) constitute an attractive class of materials for many optoelectronic applications. However, their charge transport properties are inferior to materials like graphene. On the other hand, the charge generation efficiency of graphene is too low to be used in many optoelectronic applications. Here, we demonstrate the development of ultrathin phototransistors and photonic synapses using a graphene-PQD (G-PQD) superstructure prepared by growing PQDs directly from a graphene lattice. We show that the G-PQDs superstructure synchronizes efficient charge generation and transport on a single platform. G-PQD phototransistors exhibit excellent responsivity of 1.4 × 108 AW–1 and specific detectivity of 4.72 × 1015 Jones at 430 nm. Moreover, the light-assisted memory effect of these superstructures enables photonic synaptic behavior, where neuromorphic computing is demonstrated by facial recognition with the assistance of machine learning. We anticipate that the G-PQD superstructures will bolster new directions in the development of highly efficient optoelectronic devices.

We report an in situ catalyst-free strategy to synthesize inorganic CsPbBr3 perovskite nanorods in a polymer matrix (NRs-PM) with good dimensional control, outstanding optical properties and ultrahigh environmental stability. Polarization photoluminescence (PL) imaging with high spatial resolution was carried out for the first time on single nanorod (NR) and shows a relatively high local polarization ratio (∼0.4) consistent with theoretical predictions based on a dielectric contrast model. We further demonstrate that macroscale alignment of the CsPbBr3 nanorods can be achieved through mechanically stretching the NRs-PM films at elevated temperature, without deteriorating the optical quality of the NRs. A polarization ratio of 0.23 is observed for these aligned NRs-PM films, suggesting their potential as polarized down-converters to increase the light efficiency in liquid crystal display (LCD) backlights.

A ligand-assisted swelling–deswelling microencapsulation strategy is proposed to enable full-color perovskite–polymer composites with unprecedented environmental stability and optical density tunability.

A simple and facile method to synthesize nanoplatelets of 2D Ruddlesden–Popper perovskites is presented. The nanoplatelets exhibit excellent emission in the ultraviolet region and the photodetector fabricated using the nanoplatelets shows high photodetectivity.