Synthesis of Single-Sized PbSe Magic-Sized Nanoclusters

Pranshu Puri, Brian Zhi, Chenjie Zeng*

University of Florida

Lead chalcogenide quantum dots (QDs) are important building blocks for cost-effective, solution-based optoelectronic devices including photovoltaic. Because of their large bulk exciton Bohr radius (e.g., 46 nm for PbSe) and small bandgap (e.g., 0.27 eV), the absorption peaks of PbSe QDs can be tuned across the entire visible to near-infrared (NIR) spectrum. However, the vulnerability to surface ligand oxidation poses a significant challenge to the stability of PbSe QDs. Magic-sized clusters (MSCs) could potentially enhance the stability in PbSe systems, but previous synthesis methods often yielded polydisperse distributions due to the concurrent formation of multiple species of MSCs. Drawing inspiration from successful methodologies employed in II-VI and III-V MSC synthesis, we present a robust approach to generate single-sized PbSe MSCs, thereby enabling fine-tuning of their optoelectronic properties with unprecedented precision.