Detection of UV Rays Using CdTe Quantum Dots

Abstract

Development of simple UV detection system using CdTe quantum dots (QDs) as primary detector with scintillating property on exposure to UV rays is reported. CdTe, CdTe/ZnS and CdTe/CdS QDs were synthesized in aqueous phase using mercaptosuccinic acid (MSA) as a capping agent and studied for its properties like crystallite size, band gap energy, fluorescence emission intensity and uniformity in size distribution. The prepared QDs were exposed to different radiations such as infrared (IR), ultraviolet (UV) and X-rays. The fluorescent emission was recorded by an optoelectronic circuit in terms of electrical signal. The result of this study shows that CdTe/ZnS QDs is better suited for the detection and measurement of UV rays. Hence these QDs could be used as a sensing element while fabricating nanosensor for UV detection.

Study of Physico-Chemical Changes of CdTe QDs after Their Exposure to Environmental Conditions

“…Several research works have already been reported on the response of metallic QDs to UV irradiation [32,33,[52][53][54]. Conversely, no illumination was observed when QDs were exposed to low-energy infrared radiation, and exposure of QDs to high-energy radiation such as X-rays leads to QD damage [52]. Some previous studies revealed that QD exposure to UV radiation releases heavy metal ions from these nanomaterials.…”

“…Derfus et al [33] reported the release of free Cd 2+ ions from cadmium selenide (CdSe) QDs in the presence of UV radiation as a consequence of QDs surface oxidation. It was found that CdTe QDs also respond to UV radiation [6,32,52,53]. UV exposure causes the release of Cd 2+ ions from the CdTe QD surface.…”