Self-assembly of perovskite nanoplates in colloidal suspensions.

In recent years, perovskite nanocrystal superlattices have been reported with collective optical phenomena, offering a promising platform for both fundamental science studies and device engineering. In this same avenue, superlattices of perovskite nanoplates can be easily prepared on different substrates, and they too present an ensemble optical response. However, the self-assembly and optical properties of these aggregates in solvents have not been reported to date.

Size-Dependent Photobleaching Mechanism and Kinetics Induced by Nanosecond Laser Pulses in Colloidal Semiconductor Quantum Dots.

An experimental-theoretical approach is proposed to investigate the size-dependent photobleaching of colloidal semiconductor quantum dots (QDs) excited by a nanosecond pulsed laser. In the experimental background, the ground-state absorption and photoluminescence (PL) spectra of chemically prepared QDs are monitored over an excitation time at distinct laser irradiances. The magnitude of photobleaching in the QD solution is quantified by the decay rate of the PL signal as a function of the excitation time and the laser power.

Exciton, Biexciton, and Hot Exciton Dynamics in CsPbBr Colloidal Nanoplatelets.

Lead halide perovskites have emerged as promising materials for light-emitting devices. Here, we report the preparation of colloidal CsPbBr nanoplatelets (3 × 4 × 23 nm) experiencing a strong quasi-one-dimensional quantum confinement. Ultrafast transient absorption and broadband fluorescence up-conversion spectroscopies were employed to scrutinize the carrier and quasiparticle dynamics and to obtain a full description of the spectroscopic properties of the material.

Ligand induced switching of the band alignment in aqueous synthesized CdTe/CdS core/shell nanocrystals.

CdTe/CdS core/shell quantum dots (QDs) are formed in aqueous synthesis via the partial decomposition of hydrophilic thiols, used as surface ligands. In this work, we investigate the influence of the chemical nature (functional group and chain length) of the used surface ligands on the shell formation. Four different surface ligands are compared: 3-mercaptopropionic acid, MPA, thioglycolic acid, TGA, sodium 3-mercaptopropanesulfonate, MPS, and sodium 2-mercaptoethanesulfonate, MES.