Elucidation of Photoluminescence Blinking Mechanism and Multiexciton Dynamics in Hybrid Organic-Inorganic Perovskite Quantum Dots.

Halide perovskites (ABX ) have emerged as promising materials in the past decade owing to their superior photophysical properties, rendering them potential candidates as solar cells, light-emitting diode displays, and lasing materials. To optimize their utilization into optoelectronic devices, fundamental understanding of the optical behaviors is necessary. To reveal the comprehensive structure-property relationship, CH NH PbBr (MAPbBr ) perovskite quantum dots (PQDs) of three different sizes are prepared by controlling the precipitation temperature.

Composition-Dependent Hot Carrier Relaxation Dynamics in Cesium Lead Halide (CsPbX , X=Br and I) Perovskite Nanocrystals.

Cesium-based perovskite nanocrystals (NCs) have outstanding photophysical properties improving the performances of lighting devices. Fundamental studies on excitonic properties and hot-carrier dynamics in perovskite NCs further suggest that these materials show higher efficiencies compared to the bulk form of perovskites. However, the relaxation rates and pathways of hot-carriers are still being elucidated.

Electron Transfer from Triplet State of TIPS-Pentacene Generated by Singlet Fission Processes to CHNHPbI Perovskite.

To reveal the applicability of singlet fission processes in perovskite solar cell, we investigated electron transfer from TIPS-pentacene to CHNHPbI (MAPbI) perovskite in film phase. Through the observation of the shorter fluorescence lifetime in TIPS-pentacene/MAPbI perovskite bilayer film (5 ns) compared with pristine MAPbI perovskite film (20 ns), we verified electron-transfer processes between TIPS-pentacene and MAPbI perovskite. Furthermore, the observation of singlet fission processes, a faster decay rate, TIPS-pentacene cations, and the analysis of kinetic profiles of the intensity ratio between 500 and 525 nm in the TA spectra of the TIPS-pentacene/MAPbI perovskite bilayer film indicate that electron transfer occurs from triplet state of TIPS-pentacene generated by singlet fission processes to MAPbI perovskite conduction band.