| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 1617570 | Journal of Alloys and Compounds | 2011 | 8 Pages |
Zn(1−x)CdxS and Zn(1−x)CdxS:Mn2+ semiconductor quantum dots (2–4 nm) have been prepared by a novel solvothermal route assisted microwave heating method. The growth parameters governing the smaller size and higher yield have been optimized. The synthesized QDs exhibit a significant blue shift as compared to their corresponding bulk counterpart in the UV–vis optical absorption spectrum. The dielectric constant value varies from 2.79 to 6.17 (at 40 °C, 1 kHz) depending upon the composition of the alloy; lower value corresponds to Zn0.75Cd0.25S:Mn2+ and the higher value corresponds to Zn0.25Cd0.75S:Mn2+. The crystallite size to exciton bohr radius ratio being <1 indicates a strong quantum confinement effect in both CdS and ZnS QDs. The quantum confinement effect exists in the sequence of ZnS:Mn2+ < Zn(1−x)CdxS:Mn2+ (x < 0.5) < ZnS < Zn(1−x)CdxS < CdS < CdS:Mn2+.
Research highlights▶ Cast effective solvothermal-microwave irradiation technique high yield synthesize of Cd-Zn-S:Mn2+ quantum dots (<5 nm). ▶ Ratio of reactants, appropriate solvents and annealing temperatures as optimization parameters. ▶ Extensive characterization by TEM, SEM, UV and quantum confinement analysis. ▶ Fine tuning of bandgap characteristics through material tailoring. ▶ Interesting cubic to hexagonal structural transformation upon enhancing metal acetate (Zn & Cd) to thiourea ratio from 1:1 to 1:3.
