Synthesis Of Zinc Sulfide Quantum Dots Research Articles

Facile synthesis of ZnS quantum dots at room temperature for ultra-violet photodetector applications

Zinc sulfide (ZnS) quantum dots (QDs) were synthesized using a facile, low-cost and environmentally friendly method at room temperature and ambient pressure. The structural, optical and electrical properties of the as-prepared ZnS QDs were investigated. The monodispersed crystalline ZnS QDs with an average size of 3.8 nm has been prepared, an absorption peak at 292 nm in the ultra-violet (UV) range was observed. The maximum responsivity (R) and detectivity (D*) of the ZnS QDs based photodetector under 365 nm UV light illumination were 5.8 A W−1 and 1.97 × 1013 Jones, respectively, which shows important potential application in UV detection.

Synthesis of ZnS QDs with Different Values of pH and White Light Generation from Fabrication of TPD: PMMA/ZnS Hybrid Devices

Quantum dots (QDs) of zinc sulfide (ZnS) was prepared by chemical reaction with different potential of hydrogen (pH) and used to fabricate organic quantum dot hybrid junction device. The optical properties of QDs were characterized by ultraviolet-visible (UV-Vis.) and photoluminescence (PL) spectrometer. The results show that the prepared QDs were nanocrystalline with defects formation. The energy gap (Eg)calculated from PL were 3.64, 3.53 and 3.35 eV for pH=8, 10 and 12 respectively. This decreasing of energy gaps is results of the effect the pH solution increases, which in turn leads to the shifted of the PL spectrum toward red shifted, which makes the energy bands at surface states are shallow bands. Fabrication of EL-device from ZnS QDs with different pH value was effective in efficient white light generation and can be the color of emerged light with different intensities.