Owing to their bright and tunable luminescence spectra, nanocrystals appear as a unique playground for light source design. Displays and lighting require white light sources that combine several narrow lines. As Kasha's rule prevents the emission of hot carriers, blends of multiple nanocrystal populations are currently the obvious strategy for broad-band source design.
View Article and Find Full Text PDFExerting forces on biomolecules inside living cells would allow us to probe their dynamic interactions in their native environment. Magnetic iron oxide nanoparticles represent a unique tool capable of pulling on biomolecules with the application of an external magnetic field gradient; however, their use has been restricted to biomolecules accessible from the extracellular medium. Targeting intracellular biomolecules represents an additional challenge due to potential nonspecific interactions with cytoplasmic or nuclear components.
View Article and Find Full Text PDFNarrow bandgap nanocrystals (NCs) are now used as infrared light absorbers, making them competitors to epitaxially grown semiconductors. However, these two types of materials could benefit from one another. While bulk materials are more effective in transporting carriers and give a high degree of doping tunability, NCs offer a larger spectral tunability without lattice-matching constraints.
View Article and Find Full Text PDFWhile the integration of nanocrystals as an active medium for optoelectronic devices progresses, light management strategies are becoming required. Over recent years, several photonic structures (plasmons, cavities, mirrors, etc.) have been coupled to nanocrystal films to shape the absorption spectrum, tune the directionality, and so on.
View Article and Find Full Text PDFNanocrystals (NCs) are now established building blocks for optoelectronics and their use as down converters for large gamut displays has been their first mass market. NC integration relies on a combination of green and red NCs into a blend, which rises post-growth formulation issues. A careful engineering of the NCs may enable dual emissions from a single NC population which violates Kasha's rule, which stipulates that emission should occur at the band edge.
View Article and Find Full Text PDFWhile HgTe nanocrystals (NCs) in the mid-infrared region have reached a high level of maturity, their far-infrared counterparts remain far less studied, raising the need for an in-depth investigation of the material before efficient device integration can be considered. Here, we explore the effect of temperature and pressure on the structural, spectroscopic, and transport properties of HgTe NCs displaying an intraband absorption at 10 THz. The temperature leads to a very weak modulation of the spectrum as opposed to what was observed for strongly confined HgTe NCs.
View Article and Find Full Text PDFAs nanocrystals (NCs) gain maturity, they become central building blocks for optoelectronics in devices such as solar cells and, more recently, infrared focal plane arrays. Now that the proof of concept of these devices has been established, their optimization requires a deeper understanding of their electronic and optical features to engineer their optoelectronic properties accurately. Though PbS NCs have been extensively investigated, the complex optical index of PbS NC thin films remains mostly unknown.
View Article and Find Full Text PDFBackground: Soil-transmitted helminths (STH) infections still present a global health problem. Mass drug administration (MDA) is a widely applied strategy to reduce morbidity and mortality caused by STH. Yet, this approach has some shortcomings.
View Article and Find Full Text PDFMercury telluride (HgTe) nanocrystals are among the most versatile infrared (IR) materials with the absorption of lowest energy optical absorption which can be tuned from the visible to the terahertz range. Therefore, they have been extensively considered as near IR emitters and as absorbers for low-cost IR detectors. However, the electroluminescence of HgTe remains poorly investigated despite its ability to go toward longer wavelengths compared to traditional lead sulfide (PbS).
View Article and Find Full Text PDFNow that colloidal nanocrystals (NCs) have been integrated as green and red sources for liquid crystal displays, the next challenge for quantum dots is their use in electrically driven light-emitting diodes (LEDs). Among various colloidal NCs, nanoplatelets (NPLs) have appeared as promising candidates for light-emitting devices because their two-dimensional shape allows a narrow luminescence spectrum, directional emission, and high light extraction. To reach high quantum efficiency, it is critical to grow core/shell structures.
View Article and Find Full Text PDFTo date, defect-tolerance electronic structure of lead halide perovskite nanocrystals is limited to an optical feature in the visible range. Here, we demonstrate that IR sensitization of formamidinium lead iodine (FAPI) nanocrystal array can be obtained by its doping with PbS nanocrystals. In this hybrid array, absorption comes from the PbS nanocrystals while transport is driven by the perovskite which reduces the dark current compared to pristine PbS.
View Article and Find Full Text PDFWe report the synthesis of long narrow gold nanocrystals and the study of their vibrational dynamics using inelastic light-scattering measurements. Rich experimental spectra are obtained for monodomain gold nanorods and pentagonal twinned bipyramids. Their assignment involves diameter-dependent nontotally symmetric vibrations which are modeled in the framework of continuum elasticity by taking into account simultaneously the size, shape, and crystallinity of the nanocrystals.
View Article and Find Full Text PDFZhongguo Xue Xi Chong Bing Fang Zhi Za Zhi
September 2019
Zhongguo Xue Xi Chong Bing Fang Zhi Za Zhi
November 2018
Objective: To understand the current status of chronic filariasis patients in Jiangsu Province so as to provide basic data for following-up care for them.
Methods: The patients were followed up one by one according to history archives between June and July, 2018, and the clue investigation was also conducted. The base data of the patients was collected through a face-to-face questionnaire survey and analyzed.
The use of intraband transition is an interesting alternative path for the design of optically active complex colloidal materials in the mid-infrared range. However, so far, the performance obtained for photodetection based on intraband transition remains much smaller than the one relying on interband transition in narrow-band-gap materials operating at the same wavelength. New strategies have to be developed to make intraband materials more effective.
View Article and Find Full Text PDFWe report the synthesis of nanocrystals with an optical feature in the THz range. To do so, we develop a new synthetic procedure for the growth of HgTe, HgSe, and HgS nanocrystals, with strong size tunability from 5 to 200 nm. This is used to tune the absorption of the nanocrystals all over the infrared range up to terahertz (from 2 to 65 μm for absorption peak and even 200 μm for cutoff wavelength).
View Article and Find Full Text PDFZhongguo Xue Xi Chong Bing Fang Zhi Za Zhi
March 2017
To understand the integrated ability of parasitic disease prevention and control of professional personnel of Jiangsu Province through the contest. Totally 56 players from the whole province were selected, and all the players participated in the contest. The theory knowledge and skill scores were collected and the statistical analyses were conducted.
View Article and Find Full Text PDFZhongguo Xue Xi Chong Bing Fang Zhi Za Zhi
May 2017
To know the contamination status of and in drinking water of Jiangsu Province, so as to provide the evidence for producing hygiene and safety drinking water. A total of 28 water plants of 13 cities in Jiangsu Province were selected, and the source water (10 L), chlorinated water (100 L) and tap water (100 L) were collected separately in each site. The water samples were then treated by filtration, washing, centrifuging concentration, immune magnetic separation, and immunofluorescent assay, to detect the numbers of cysts and oocysts.
View Article and Find Full Text PDFZhongguo Xue Xi Chong Bing Fang Zhi Za Zhi
July 2017
Objective: To evaluate the effect of the prevention and control technique training of human important parasitic diseases for basic professional and technical personnel in Jiangsu Province in 2017.
Methods: A workshop including theory courses and practical operations was carried out for the basic professional and technical personnel. At the end of the workshop, the effects were evaluated through the theoretical and microscopic examinations.
We investigate the potential use of colloidal nanoplates of SbTe by conducting transport on single particle with in mind their potential use as 3D topological insulator material. We develop a synthetic procedure for the growth of plates with large lateral extension and probe their infrared optical and transport properties. These two properties are used as probe for the determination of the bulk carrier density and agree on a value in the 2-3 × 10 cm range.
View Article and Find Full Text PDFZhongguo Xue Xi Chong Bing Fang Zhi Za Zhi
June 2016
Objective: To understand the status of soil-transmitted nematode infections in rural residents so as to provide the evidence for formulating the guidance for prevention and control of the diseases.
Methods: The national surveillance sites of soil-transmitted nematode infections were established in Shuyang County, Suqian City, Jiangsu Province from 2006 to 2015. At least 1 000 fecal samples of residents aged 3 years or above were collected in every autumn, and the intestinal helminth eggs were detected with the Kato-Katz technique and the eggs were detected by the cellophane tape method for children aged 3-12 years.
Zhongguo Xue Xi Chong Bing Fang Zhi Za Zhi
December 2015
Objective: To understand the endemic situation of Clonorchis sinensis in its second intermediate hosts in Pizhou and Xinyi cities of Jiangsu Province, so as to provide the evidence for the further control and treatment.
Methods: Pseudorasbora parva and Abbottina rivularis were caught from the natural water body of Pizhou and Xinyi cities, and the tabletting microscopy method was applied to test the metacercaria of C. sinensis.
Infrared thermal imaging devices rely on narrow band gap semiconductors grown by physical methods such as molecular beam epitaxy and chemical vapor deposition. These technologies are expensive, and infrared detectors remain limited to defense and scientific applications. Colloidal quantum dots (QDs) offer a low cost alternative to infrared detector by combining inexpensive synthesis and an ease of processing, but their performances are so far limited, in terms of both wavelength and sensitivity.
View Article and Find Full Text PDFZhongguo Xue Xi Chong Bing Fang Zhi Za Zhi
April 2015
Zhongguo Xue Xi Chong Bing Fang Zhi Za Zhi
August 2014
Objective: To understand the current status of infections of intestinal parasites of population in Taixing City, Jiangsu Province.
Methods: The infection rates and densities of human intestinal parasites were investigated according to the methods of the National Investigation Scheme on Human Principal Parasites, and the data of society, economy and disease control were collected and analyzed.
Results: Among 2 556 people investigated in five villages, 16 persons were found with intestinal parasites, with an infection rate of 0.