Quantum Dot Composite Radiation Detectors

Urdaneta, Mario; Stepanov, P.Yu.; Weinberg, I.; Pala, Irina R.; Brock, Stephanie L.

doi:10.5772/10598

Cited by 2 publications

(3 citation statements)

References 20 publications

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“…Most types of vacuum photo detectors are sensitive to external magnetic fields and therefore magnetic shielding for certain environments are preferred. Solid state photomultiplier tubes have high noise, very sensitive to temperature and supply voltage variations (Urdaneta et al, 2011). This paper focuses on the development of a simple UV detection system using quantum dots based on the principle of scintillation.…”

Section: Figure 1 Optical Properties Of Quantum Dotsmentioning

confidence: 99%

“…The basic principle of the scintillation detector is the use of a special material which glows or "scintillates" when radiation interacts with it e.g. a type of salt called sodium-iodide (Urdaneta et al, 2011;Knoll & Glenn, 2010). The light produced from the scintillation process is reflected through a clear window where it interacts with device called photomultiplier tube, which converts light into electrical signals (Sheng et al, 2002).…”

Section: Figure 1 Optical Properties Of Quantum Dotsmentioning

confidence: 99%

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Detection of UV Rays Using CdTe Quantum Dots

Anbarasi¹,

Kalpana²,

Arivarasan

et al. 2015

International Journal of Measurement Technologies and Instrumentation Engineering

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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.

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Section: Figure 1 Optical Properties Of Quantum Dotsmentioning

confidence: 99%

Section: Figure 1 Optical Properties Of Quantum Dotsmentioning

confidence: 99%

Detection of UV Rays Using CdTe Quantum Dots

Anbarasi¹,

Kalpana²,

Arivarasan

et al. 2015

International Journal of Measurement Technologies and Instrumentation Engineering

View full text Add to dashboard Cite

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“…Semiconducting nanocrystals (NC) based on metal chalcogenides exhibit significant promise in technical applications because of the easily tunable band gap throughout much of the visible spectrum, controlled by the size and shape of the nanocrystals, as well as their ease of synthesis. Accordingly, this class of semiconducting quantum dots (QDs) is of considerable interest for optoelectronic device applications such as field-effect transistors (FETs), , photodetectors, , light-emitting diodes (LEDs), − solar cells, , and radiation detectors. − However, to realize applications based on facile carrier transport, metal chalcogenide NCs need to be interfaced together. Thus, considerable focus has been placed on exchanging the long-chain insulating ligands typically employed in NC synthesis with shorter and more labile passivating ligands for the improvement of charge transport in devices , as well as other passivation techniques such as the use of molecular metal chalcogenide complexes as ligands for colloidal NCs or halide passivation on the NC surface for solution-based passivation. − …”

Section: Introductionmentioning

confidence: 99%

Role of Crystal Structure and Chalcogenide Redox Properties on the Oxidative Assembly of Cadmium Chalcogenide Nanocrystals

2017

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Oxidative assembly of metal chalcogenide nanocrystals (NCs) enables the formation of 2-D (dense) and 3-D porous structures without the presence of intervening ligands between particles that can moderate transport properties. This route has been demonstrated to be successful for a range of single-component structures including CdQ, PbQ, and ZnQ (Q = S, Se, Te). En route to the controllable assembly of multicomponent nanostructures, the roles of Q redox properties (2Q2− → Q22− + 2e) responsible for particle cross-linking and the native structure (cubic zinc blende vs hexagonal wurtzite) in the kinetics of assembly in single-component CdQ NCs are evaluated using time-resolved dynamic light scattering (TR-DLS). For wurtzite CdQ, the rates follow the ease of oxidation, with telluride as the fastest, followed by selenide and sulfide. However, when comparing CdS wurtzite (w) and zinc blende (zb), the cubic NCs exhibit surprisingly slow kinetics. NMR studies reveal the zb structure to have lower ligand coverage (by a factor of 4) relative to that of w, and the formation of free disulfide (the product of ligand oxidation) is slow. This is attributed to differences in the surface energies of w and zb facets, with w having polar (0001) facets of high energy compared to the neutral facets of the zb structure. The zb-CdS NCs prepared by low-temperature synthesis methods are likely to suffer from surface defects that may moderate reactivity. EPR studies suggest that zb-CdS has paramagnetic sulfur vacancies not present in w-CdS. These data suggest that structure plays an unexpectedly large role in the kinetics of CdQ NC oxidative assembly, providing a useful lever to moderate activities in multicomponent assemblies.

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Quantum Dot Composite Radiation Detectors

Cited by 2 publications

References 20 publications

Detection of UV Rays Using CdTe Quantum Dots

Detection of UV Rays Using CdTe Quantum Dots

Role of Crystal Structure and Chalcogenide Redox Properties on the Oxidative Assembly of Cadmium Chalcogenide Nanocrystals

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