Composition-tuned photoluminescence spectra of colloidal CdSe_xS_1-x ternary nanoalloys

The colloidal CdSexS1-x ternary nanoalloys were prepared by fine-tuning the chemical composition using phosphine-free solvents. With an increase in Se content, the bandgaps may be changed from 2.81 to 1.95 eV. The influence of lattice strain on the carrier dynamics of CdSexS1-x nanoalloys has been investigated. The structural investigation of the nanoalloys reveals a linear expansion of the Zinc cubic lattice with increasing S content, demonstrating that the lattice strain was caused by the difference between Cd-S and Cd-Se bond lengths. Photoluminescence decay time of CdSexS1-x nanoalloys decreased with increasing lattice constant, indicating that lattice strain affects both radiative and nonradiative relaxation rates.