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Optical Nanoprobes for Diagnosis
Published in D. Sakthi Kumar, Aswathy Ravindran Girija, Bionanotechnology in Cancer, 2023
R. G. Aswathy, D. Sakthi Kumar
These unique properties lead to QDs of different-size emitting lights of different wavelengths from ultraviolet to infrared spectrum. For example, the bulk bandgap of semiconductor cadmium selenide (CdSe) is 1.7 eV corresponding to 730 nm light emission. By changing the nanocrystal diameter of CdSe from 2 nm to 7 nm, it can be tuned to emit light with wavelength between 450 nm and 650 nm. The material composition can also be used as another factor for the modification of band gap of the semiconductor. By changing the composition of the alloy CdSexTe1–x of 5 nm size can be tuned to emit light in 610–800 nm. The size and shape of semiconductor QDs can be specifically controlled by factors such as experimental duration, temperature, and concentration of precursor molecules in the synthesis.
Nanobiotechnology
Published in Firdos Alam Khan, Biotechnology Fundamentals, 2020
In addition, nanosensors may be able to detect macroscopic variations from outside the body and communicate these changes to other nanoproducts working within the body. One example of nanosensors involves using the fluorescence properties of cadmium selenide qdots as sensors to uncover tumors within the body. By injecting a body with these qdots, a doctor could see where a tumor or cancer cell was by finding the injected qdots—an easy process because of their fluorescence. Developed nanosensor qdots would be specifically constructed to find only the particular cell to which the body was at risk. A downside to the cadmium selenide qdots, however, is that they are highly toxic to the body. As a result, researchers are working on developing alternate qdots made from a different, less toxic material, while still retaining some of the fluorescence properties. They have been investigating the specific benefits of zinc sulfide qdots, which, though not quite as fluorescent as cadmium selenide qdots, can be augmented with other metals, including manganese and various lanthanide elements.
Nano-biotechnology
Published in Firdos Alam Khan, Biotechnology Fundamentals, 2018
In addition, nanosensors may be able to detect macroscopic variations from outside the body and communicate these changes to other nanoproducts working within the body. One example of nanosensors involves using the fluorescence properties of cadmium selenide qdots as sensors to uncover tumors within the body. By injecting a body with these qdots, a doctor could see where a tumor or cancer cell was by finding the injected qdots—an easy process because of their fluorescence. Developed nanosensor qdots would be specifically constructed to find only the particular cell for which the body was at risk. A downside to the cadmium selenide qdots, however, is that they are highly toxic to the body. As a result, researchers are working on developing alternative qdots made out of a different, less toxic material, while still retaining some of the fluorescence properties. In particular, they have been investigating the specific benefits of zinc sulfide qdots, which, though not quite as fluorescent as cadmium selenide qdots, can be augmented with other metals, including manganese and various lanthanide elements.
Influence of air annealing temperature on physical properties of MgF2 -treated CdSe thin films: phase transition and grain growth
Published in Phase Transitions, 2023
Suman Kumari, G. Chasta, N. Kumari, M.S. Dhaka
In the present scenario of the technological world, thin films of II-VI group’s semiconductor materials have received remarkable attention due to their wide range of applications in light-emitting diodes, solar cells, photo-electrochemical cells, solar selective coatings, bio-medical applications, sensors, lasers, electronic and optoelectronic devices, photo-catalysis, thin film transistors, electroluminescent devices, photo- and gamma-ray detectors, etc [1–4]. Cadmium selenide (CdSe) is prominent material among the II-VI group binary compounds where Cadmium (Cd) and Selenium (Se) belong to the IIA and VIB groups of the periodic table, respectively [5]. The CdSe thin films could be employed for optoelectronic and photovoltaic applications because of their suitable direct optical energy band gap of about 1.74 eV. The CdSe material could induce large absorption of light in the visible region due to a higher absorption coefficient (∼105 per cm) and it has n-type conductivity.
High-temperature thermodynamic properties of nanocrystalline CdSe thin film
Published in Surface Engineering, 2018
Fei Xiao, Min Zhang, Hui Yang, ShunYong Wei, Qiya Liu, Taihong Chen, Tixian Zeng
Cadmium selenide (CdSe) is a II–VI compound semiconductor which has a hexagonal close packed wurtzite structure and belongs to the P63mc at normal temperature and pressure. The notable properties of CdSe crystals have a suitable direct band gap (Eg = 1.74 eV) [1] for the visible light band in the solar spectrum and the large average atomic number (Zavg = 41), which provides resistance to high-energy radiation. CdSe has been extensively investigated due to its potential utility in various applications such as solar cells [2], hybrid white light emitter device [3], photoelectric sensor [4], photocatalytic [5], biomarkers [6] and optical fibre [7].
Tailoring the physical parameters of ferroelectric liquid crystal mixture with cadmium selenide quantum dots
Published in Liquid Crystals, 2023
Gagandeep Kaur, Poonma Malik, Sushma Yadav, Praveen Malik
Cadmium selenide (CdSe) QDs, belonging to group II-IV elements, are popular amongst the QDs due to high luminescence and quantum yield. CdSe QDs provoked as fluorescent tags for light emitting diodes, lasing and solar cell applications [20–22]. Interfacial charge transfer in FLC-QDs nanocomposites is one of the important characteristics which modulates the local electric field [23–25]. This will further help in elucidating the underlying interaction mechanism responsible for the modification of FLC’s properties.