Dimensional tunability in S N 2-based synthesis of CsPbI 3 perovskite nanocrystals via regulating lattice-forming behavior of surface ligands
Year: 2025
Type: article
Abstract: Lead-halide perovskite nanocrystals (PNCs) exhibit exceptional optical properties with size- and dimension-tunable optical bandgaps, making them promising for diverse optoelectronic applications. The dimensionality of PNCs has been controlled by tuning the oleic acid (OA)/oleylamine (OLA) feed ratio in conventional injection-based synthesis. Although the emerging bimolecular nucleophilic substitution (SN2)-based heat-up synthesis enables the production of high-quality and monodisperse PNCs, achieving dimensional tunability by altering the OA/ OLA feed ratio remains challenging in this approach. Herein, we present an integrated strategy for controlling the dimensionality and surface properties of CsPbI3-PNCs based on the SN2-based heat-up method. Our approach focuses on the regulation of OLA protonation and oleylammonium (OAM+) lattice-forming behavior. Using chemical analysis, we identify the protonation routes of OLA in SN2 reactions and demonstrate that adjusting the acid–base and SN2 reactions involving OA and OLA can reduce OLA protonation and the subsequent formation of OAM⁺. Furthermore, by enhancing the competitive lattice-forming behavior of Cs+ over OAM+, we suppress excessive surface termination by OAM+. These approaches achieve dimensional tunability between 2D nanoplatelets and 3D nanocubes in the SN2-based heat-up synthesis, along with subsequent spectral control of optical features. To independently optimize their surface passivation, we employ a post-synthetic passivation (PSP) strategy using OAM+–I– pairs, which increases the photoluminescence quantum yield of PNCs from 71.9% to 81.7% by reducing surface defects.
Source: Nano Research
Language: English
Subfield: Electrical and Electronic Engineering
Field: Engineering
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $5,290
OpenAlex ID: W4413423960