Structural, morphological, electrochemical and optical properties ZnS quantum dots: Influence of La3+ ions

Abstract

The La-doped ZnS quantum dots were prepared by the facile co-precipitation technique. XRD patterns revealed the cubic structure of the ZnS crystal lattice. We measure the size of the synthesized nanoparticles at approximately 2 nm. Sulfur vacancies on the structure’s surface produce some defects. The HR-TEM and FE-SEM results also confirm the size, morphology, and other structural entities. The EDS and FTIR results confirmed the composition of the samples. We tested the electrochemical behaviors of the samples, and found that La 4 at% doped-ZnS offered a high specific capacitance. The enhancement of optical absorbance was observed by the UV–vis studies. A red shift was received in band gap due to incorporation of La ions. We observe high optical transmittance for La 2 at.% doped-ZnS quantum dots. PL emission results showed a weak emission in the UV region, and some defect-related emissions in the visible region.

Keywords

• Quantum dots
• La
• ZnS
• Red shift
• Photoluminescence
• Specific capacitance