Quickest single-step one pot mechanosynthesis and characterization of ZnTe quantum dots

ZnTe quantum dots (QDs) are synthesized at room temperature in a single step by mechanical alloying the stoichiometric equimolar mixture (1:1 mol) of Zn and Te powders under Ar within 1 h of milling. Both XRD and HRTEM characterizations reveal that these QDs having size ∼5 nm contain stacking faults of different kinds. A distinct blue-shift in absorption spectra with decreasing particle size of QDs confirms the quantum size confinement effect (QSCE). It is observed for first time that the QDs with considerable amount of faults can also show the QSCE. Optical band gaps of these QDs increase with increasing milling time and their band gaps can be fine-tuned easily by varying milling time of QDs.

Research highlights
► First time quickest mechanosynthesis of ZnTe QDs starting from Zn and Te powders.
► Cubic ZnTe are formed in a single pot at RT in a single step within 1 h of milling.
► The existence of stacking faults and twin faults are evident from HRTEM images.
► Distinct blue shift has been observed in UV–vis absorption spectra.
► First time report that ZnTe QDs with faults can also show the quantum size effect.