Study of a series of lanthanides-doped ZnS quantum dots' optoelectronic properties for UV photodetector device applications

We studied the optoelectronic properties of the ZnS quantum dot doped by Lanthanide series [Xe] 6s(2) 4f (n) with 6 <= n <= 9, including Gd: [Xe] 6s(2) 4f(7) 5d(1). The I-V characteristics of the RE-doped ZnS QDs were studied under near-UV exposure (395 nm) and darkness. Compared to the rest of the series, the data showed photocurrent elevation by 56% as the Eu-doped ZnS was exposed to UV relative to darkness exposure. Therefore, the Eu-doped ZnS is expected to be a good contribution to the photosensors and optical switches applications. Doping ZnS with a set of Lanthanides did not affect its zinc blind phase, despite their large ionic radii. However, a shift toward a lower diffraction angle in the XRD pattern indicated the inclusion of the Lanthanides into the ZnS structure. Additionally, the grain size almost increased with n. TEM study revealed spherical particles with an average diameter of 4.9 nm. Photoluminescence, XPS, and UV-vis studies were carried out on the series. The average bandgap energy of the QDs was about an average value of 3.76 eV.

Automated summary

We investigated the optoelectronic properties of ZnS quantum dots doped with Lanthanide series [Xe] 6s(2) 4f (n) with 6 <= n <= 9, including Gd: [Xe] 6s(2) 4f(7) 5d(1). The I-V characteristics of the RE-doped ZnS QDs were studied under near-UV exposure (395 nm) and darkness. The results showed that the Eu-doped ZnS exhibited a 56% increase in photocurrent under UV exposure compared to darkness, suggesting its potential for photosensors and optical switches applications. Doping with Lanthanides did not affect the zinc blind phase of ZnS, but it did cause a shift in the XRD pattern and an increase in grain size.