From Magic Size to Atomic Precision: Facile Synthesis of a CdTe Semiconductor Nanocluster.

Facile synthesis of atomically precise semiconductor nanoclusters remains an important challenge, especially for those with heavier chalcogens. Combining coordination and colloidal methods, we developed a simple approach for synthesizing an atomically precise CdTe nanocluster with high purity and stability. Specifically, a precise cadmium-thiolate compound, [Cd(SR)], was reacted with a facile phosphine telluride (TePR) precursor to produce a CdTe magic-sized cluster with a distinct absorption peak at 377 nm and a narrow linewidth of 20 nm.

Mapping the reaction zones for CdTe magic-sized clusters and their emission properties.

CdTe magic-sized clusters (MSCs) are promising building blocks for semiconductor devices because of their single size, consistent properties, and reproducible synthesis. However, the synthetic conditions for CdTe MSCs vary significantly in different reports, which hinders the general understanding of their formation mechanisms. Here, we employed Cd(oleate), trioctylphosphine telluride (TOPTe), and oleylamine, which are commonly used for larger quantum dot (QD) synthesis, as standard reaction precursors, and systematically investigated the effects of solvent, phosphine amount, oleylamine amount, Cd : Te ratio, and temperature on the evolution of MSCs with time.