ABSTRACT ZnSxO,-x with x=1.0 (Pure ZnS),0.8,0.6,0.5, 0.4, 0.2 and 0.0 (Pure ZnO) quantum dots were prepared by using Mahadevan"s method which is nothing but a simple solvothermal method that involves the usage of domestic microwave oven and simple chemicals. UV-Vis-NIR absorption, photoluminescence (PL) and photoconductivity (PC) measurements were carried out to understand the optical properties of the prepared quantum dots. The UV absorption edges of all quantum dots show a blue shift and fall within 310-350 ran except for ZnO which is around 370 ran. Further, ZnSo.sOo.s exhibits the minimum. The PL spectra have five prominent peaks (two peaks coupled) around 408, 446, 486, 490 and 530 ran indicating clearly that the mixed quantum dots (nanocomposites) have very high PL yield compared to that of end members (ZnS and ZnO). Similarly, the photo current gains observed for mixed ones are higher than that for ZnS and ZnO. Enhancement in these optical properties explains that the mixed (nanocomposite) quantum dots are expected to be more useful in fabricating opto-electonic devices such as solar cells, infrared windows, sensors and displays. Also, they are expected to be used in integrated optic devices such as switches, filters, optical testers, etc.
展开▼
