Stabilizing and accessing across ternary phase cesium lead bromide perovskite nanocrystals: thermodynamic and kinetic controls

Autor: Seonhong Min, Hyejin Choe, Junsang Cho
Rok vydání: 2022
Předmět:
DOI: 10.6084/m9.figshare.20379871.v1
Popis: Lead halide perovskites with fascinating optoelectronic properties have enabled rapid advancement and development in photovoltaics and light-emitting diodes. However, accessing and stabilizing the complex ternary phase space diagram (Cs-Pb-Br) of perovskites including 3 D nanocrystals, 2 D nanoplatelets, and 0 D hexagonal platelets with desirable optoelectronic properties further requires a deeper understanding of the thermodynamic and kinetic aspects regarding the growth of lead halide perovskite nanocrystals. In this work, we have mapped out the multivariant synthetic design spaces observed in the ternary phase diagram of Cs-Pb-Br to evaluate the effect of controlling thermodynamic equilibrium state (e.g. chemical potentials of the Cs:Pb ratio) and growth kinetics with ligand concentration (oleylamine). Further in-situ tracking of reversible phase transformation with the addition of oleylamine (forward) and PbBr2 (reverse) exhibiting distinctive spectroscopic signatures between 3 D and 0 D phases (vice versa) can provide insight into the reversible phase transformation mechanism and important role of PbBr2 species that can modify the bonding motif and connectivity of [PbBr6]4- octahedral frameworks.
Databáze: OpenAIRE