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Background Immunochromatographic test strip (ICTS) has become one of the most widely used rapid diagnostics platforms for the point-of-care testing of various contaminant residues in food. However, traditional gold nanoparticle (AuNP)-based ICTSs suffer limited sensitivity ranged from ng/mL to μg/mL, thus severely hindering them from meeting the increasing demand for trace target detection. Scope and approach The use of novel nanomaterials with high signal strength to replace AuNPs as signal probes is considered as the most effective strategy to enhance the sensitivity of ICTS nanosensor. Among them, highly luminescent nanomaterials have attracted increasing interest in improving the detection performance of ICTS due to its advantages of visualization, quantitation, multiplexing, anti-jamming capability, and high sensitivity. Currently available nanomaterials include dye-based fluorescent nanomaterials, semiconductor quantum dots and its nanobeads, up-conversion nanoparticles, time-resolved fluorescence nanomaterials, aggregation-induced emission nanomaterials, noble metal nanoclusters, and magnetic fluorescent nanomaterials, and they have been successfully applied for detecting various hazardous substances, including pesticide and veterinary drug residues, food additives, mycotoxins, heavy metal ions, allergens, and microorganisms. In this review, thus we comprehensively summarize the application potentials and critical roles of such nanomaterials as signal reporters in current ICTS systems to ensure food safety. Key findings and conclusions A detailed classification of signal probes with emphasis on the inherent advantage, synthesis, signal amplification strategy, and further improvement of each luminescent nanomaterial was discussed and the state-of-the-art of commercial fluorescent ICTS kits and readers for food safety was summarized. Further improvement should focus on the design and development of high-quality luminescent nanomaterials, ultra-sensitive detection, multiplexing and multimode sensing, accurate quantification, and intelligent signal reading.

The fascinating optoelectronic properties of semiconductor quantum dots (QDs) originate from the quantum confinement effect; i.e., the band gap increases as the size decreases. Another significant ...

International audience; Doping of transition metals within a semiconductor quantum dot (QD) has a high impact on the optical and magnetic properties of the QD. In this study, we report the synthesis of Mn 2+-doped Ag−In−Ga−Zn−S (Mn:AIGZS) QDs via thermolysis of a dithiocarbamate complex of Ag + , In 3+ , Ga 3+ , and Zn 2+ and of Mn(stearate) 2 in oleylamine. The influence of the Mn 2+ loading on the photoluminescence (PL) and magnetic properties of the dots are investigated. Mn:AIGZS QDs exhibit a diameter of ca. 2 nm, a high PL quantum yield (up to 41.3% for a 2.5% doping in Mn 2+), and robust photo-and colloidal stabilities. The optical properties of Mn:AIGZS QDs are preserved upon transfer into water using the glutathione tetramethylammonium ligand. At the same time, Mn:AIGZS QDs exhibit high relaxivity (r 1 = 0.15 mM −1 s −1 and r 2 = 0.57 mM −1 s −1 at 298 K and 2.34 T), which shows their potential applicability for bimodal PL/magnetic resonance imaging (MRI) probes.

Creation of various photoluminescent nanomaterials has significantly expanded the arsenal of approaches used in modern biomedicine. Their unique photophysical properties can significantly improve the sensitivity and specificity of diagnostic methods, increase therapy effectiveness, and make a theranostic approach to treatment possible through the application of nanoparticle conjugates with functional macromolecules. The most widely used nanomaterials to date are semiconductor quantum dots; gold nanoclusters; carbon dots; nanodiamonds; semiconductor porous silicon; and up-conversion nanoparticles. This paper considers the promising groups of photoluminescent nanomaterials that can be used in medical biotechnology: in particular, for devising agents for optical diagnostic methods, sensorics, and various types of therapy.

A theoretical investigation is performed to determine the possibility of and conditions for self-induced transparency on Wannier–Mott excitons in a layer of semiconductor quantum dots.

Magic-sized nanoclusters have gained tremendous attention from researchers as they offer applicability in a variety of fields ranging from chemistry and physics to electronics. The first report on magic-sized nanoclusters of CdSe gave impetus to deepen the understanding of the sub 2 nanometer (

We demonstrate a Purcell-enhanced single-photon source realized by the fabrication of a hybrid III–V/dielectric circular Bragg grating cavity directly bonded onto a piezoelectric actuator. Such a k...

Metal–organic framework (MOF) based light harvesting has been attracting considerable attention as an artificial antenna for photochemical and photophysical applications. Herein, we report the phot...

Over the last decade, narrow-band emitters have been recognized as key enablers for light emitting diodes (LEDs) backlights in liquid-crystal displays (LCDs) by competing with other display technologies. Today, efforts have been devoted to the exploration of narrow-band green/red luminescent materials with high quantum efficiency and excellent stability to optimize the performance of LED backlights. This review first presents an overview of the significant progress made in the development of narrow-band emitters used in LED backlights for LCDs with the emphasis on the versatile materials databases from doped phosphors to luminescent II–VI, III-V semiconductor quantum dots, and the recent halide perovskites nanocrystals and bulk metal halides. Subsequently, the correlation of structure-luminescence properties, and the device performance optimization of these emitters have been analyzed. The focus is placed on summarizing and comparing the remarkable examples of outdated and new narrow-band luminescent materials as potential candidates in LED backlights. Finally, the outlooks and challenges in discovering new narrow-band emitters have been proposed.

Photoluminescence (PL) on/off switching systems using photochromic molecules have a high potential for a wide range of applications, such as optical memories, chemo- and biosensing, and superresolu...

The continued growth in the demand of data storage and processing has spurred the development of high-performance storage technologies and brain-inspired neuromorphic hardware. Semiconductor quantum dots (QDs) offer an appealing option for these applications since they combine excellent electronic/optical properties and structural stability and can address the requirements of low-cost, large-area, and solution-based manufactured technologies. Here, we focus on the development of nonvolatile memories and neuromorphic computing systems based on QD thin-film solids. We introduce recent advances of QDs and highlight their unique electrical and optical features for designing future electronic devices. We also discuss the advantageous traits of QDs for novel and optimized memory techniques in both conventional flash memories and emerging memristors. Then, we review recent advances in QD-based neuromorphic devices from artificial synapses to light-sensory synaptic platforms. Finally, we highlight major challenges for commercial translation and consider future directions for the postsilicon era.

In this presentation a review about the current state of the art concerning the application of deterministic single photon sources for absolute radiometry, i.e. the calibration of single photon detectors, is given. At the Physikalisch-Technische Bundesanstalt, the German national Metrology institute, an extensive research is carried out to optimize single photon sources for this purpose. Different single photon sources are currently under investigation, these are sources based on defect centres in (nano-)diamonds, on molecules and on semiconductor quantum dots.

The possibility and conditions of recording and reading out two-quantum transient holograms on the exciton levels of CdSe/CdS/ZnS-type semiconductor quantum dots are studied theoretically.

Herein, for the first time, the role of double-layer electron transporting layer (ETL), i.e. ZnO/SnO 2 on the efficiency of lead sulfide quantum dots solar cells is demonstrated. Using this approach, a device with power conversion efficiency of 10.6% is achieved mainly due to the enhancement of open circuit voltage ( V OC ). The authors reduce the loss-in-potential by 80 mV using ZnO/SnO 2 double-layer ETL.

International audience; Semiconductor quantum dots (QDs) embedded into polymer microbeads are known to be very attractive emitters for spectral multiplexing and colour encoding. Their luminescence lifetimes or decay kinetics have been, however, rarely exploited as encoding parameter, although they cover time ranges which are not easily accessible with other luminophores. We demonstrate here the potential of QDs made from II/VI semiconductors with luminescence lifetimes of several 10 ns to expand the lifetime range of organic encoding luminophores in multiplexing applications using time-resolved flow cytometry (LT-FCM). For this purpose, two different types of QD-loaded beads were prepared and characterized by photoluminescence measurements on the ensemble level and by single-particle confocal laser scanning microscopy. Subsequently, these lifetime-encoded microbeads were combined with dye-encoded microparticles in systematic studies to demonstrate the potential of these QDs to increase the number of lifetime codes for lifetime multiplexing and combined multiplexing in the time and colour domain (tempo-spectral multiplexing). These studies were done with a recently developed novel luminescence lifetime flow cytometer (LT-FCM setup) operating in the time-domain, that presents an alternative to reports on phase-sensitive lifetime detection in flow cytometry. Flow cytometry (FCM), where either single cells or particles are optically detected in a flow, is an established and widespread multiparametric fluorescence technique used for many routine and research applications in biology, medical diagnostics, and food analysis 1-5. FCM typically relies on organic luminophores for optical encoding and multiplexing as well as analyte quantification 6-10. State-of-the-art FCM instruments are designed to detect spectral and/or intensity codes and can distinguish a large number of different colour and intensity codes, e.g. in the case of bead-based assays 5,11-13. Commonly applied spectral multiplexing approaches utilizing organic lumi-nophores are, however, limited by the spectral overlap of the emission bands of the different encoding dyes which limits the number of distinguishable codes and can require signal compensation and cross talk correction 6,14,15. The exploitation of the luminophore-characteristic luminescence lifetime (LT) as additional encoding parameter could in principle increase the number of accessible codes in flow cytometry analysis, thereby increasing the degree of multiplexing 6,7,14,16-21. Time-resolved fluorescence measurements in flow cytometry and lifetime encoding have been discussed for decades 8,22-28. The concept of lifetime multiplexing in a flow, however, has not been adopted in routine applications up to now due to the limited measurement time per object resulting in reduced photon count numbers 27,29. Moreover, the vast majority of reports on lifetime detection in flow cytometry relies on frequency-domain techniques (phase fluorometry), which used to be less expensive as fast detectors required for photon counting-based detection in the time domain, and present specific applications 8,9,14,18,28,30-32. This has been highlighted e.g., in a recently published comprehensive review article from J.P. Houston et al. 8 , revealing only a very small number of research articles related to cytometry studies in the time domain, mostly associated

Light-emitting diodes based on II–VI semiconductor quantum dots (QDs) have attracted considerable attention due to their superior features of color tunability, high brightness, narrow emission bandwidths, solution processing capabilities and compatibility with flexible substrates. The efficiencies and stabilities of red and green quantum-dot light-emitting diodes (QLEDs) are close to the standard for commercial applications, while blue QLEDs lag behind in device efficiency and stability. This paper reviews the latest progress of blue luminescent materials and devices based on II–VI semiconductor QDs, covering the latest progress in the synthesis of blue QDs, device structures, carrier transport materials, interface regulation, and light outcoupling technology. Furthermore, the current problems and solutions of blue QLEDs are discussed, and the development and application prospects of blue QLEDs are summarized. Key issues and challenges associated with the application of QLEDs in flat-panel displays are also identified.

In this paper, we investigate the potential of submonolayer-grown InAs:Sb/GaAs quantum dots as active medium for opto-electronic devices emitting in the 1060 nm spectral range. Grown as multiple sheets of InAs in a GaAs matrix, submonolayer quantum dots yield light-emitting devices with large material gain and fast recovery dynamics. Alloying these structures with antimony enhances the carrier localization and red shifts the emission, whereas dramatically broadening the optical bandwidth. In a combined experimental and numerical study, we trace this effect to an Sb-induced bimodal distribution of localized and delocalized exciton states. While the former do not participate in the lasing process, they give rise to a bandwidth broadening at superluminescence operation and optical amplification. Above threshold laser properties like gain and slope efficiency are mainly determined by the delocalized fraction of carriers.

A new technique for estimating the efficiency of electron transfer from a CdSe/ZnS quantum dot (QD) to TiO2 nanoparticles based on the generation of reactive oxygen species by hybrid structures is presented. It was demonstrated that in the formed multilayer hybrid structures of TiO2/QD, photoinduced electron transfer is realized with an efficiency of 26%.

In this paper, the propagation of light soliton is studied in nonlinear optical fiber. We propose the external excitation of SQD waveguides through an optical source that allows the generation of solitary waves that are propagated through a non-linear optical fiber. The soliton formation is studied theoretically from the non-linear interaction between the external optical excitation and SQDs, considering SQDs as a quantum system of three energy levels. In this study, the Fourier Split-Step (FSS) method is used to solve numerically continuous nonlinear Schrodinger equation (NLSE) to evolution of the soliton pulse emitted by the SQDs inside an optical fiber with real physical parameters. The effect of SQDs density and electric field on the pulse width is also studied. Phase plane portraits are drawn for the stability of soliton in fiber and SQDs using software Matcont.

Metastable multiexcitonic states (MESs) of semiconductor quantum dots can be involved in multielectron transfer reactions, which opens new perspectives in nanomaterials-based optoelectronic applications. Herein, we demonstrate the generation of a MES in CsPbBr3 perovskite quantum dots (PQDs) and its dissociation dynamics through multiple electron transfers to molecular electron acceptors, anthraquinones (AQs), bound to the PQD surface by a carboxylic anchor. As many as 14 excitons are produced at an excitation density of roughly 220 μJ cm-2 without detectable PQD degradation. Addition of AQ results in the formation of PQD-AQ hybrids with excess of AQs (PQD:AQ ≈ 1:20), which opens the possibility of multielectron transfer acts from MES to AQs. We found that the electron transfer saturates after roughly five transfer acts and that the first electron transfer (ET) time constant is as short as 1 ps. However, each ET increases the Coulomb potential barrier for the next ET, which decreases the rate of ET, resulting in a saturation after five ETs. publishedVersion

We present results for the nonlinear optical rectification of an asymmetric GaAs/AlGaAs quantum dot structure coupled to a gold nanosphere under the influence of a strong electromagnetic field. We show that the nonlinear optical rectification coefficient depends strongly on the distance between the quantum dot and the metallic nanosphere and on the direction of the applied electromagnetic field.

Semiconductor particles in the range of 2-10 nm are known as quantum dots (QDs) and nano-crystals where in all the three spatial dimensions, excitons are confined. Because of very small size and special electronic properties, QDs are expected to be building blocks of many electronic and optoelectronic devices. These particles possess tunable quantum efficiency, continuous absorption spectra, narrow emission and long term photostability. These are important for various biomedical applications. In this chapter definition of semiconductor QDs, their methods of preparation and characterization along with their properties and applications have been discussed.

International audience; Single photons are the cornerstones of many applications in quantum technologies, from quantum computing to quantum networks. A new technology for the generation of single-photons has recently emerged, allowing a ten-time increase in efficiency with near-unity quantum purity. These single-photon sources are based on semiconductor quantum dots in optical microcavities.

International audience

QDs are excellent materials for bioimaging because of its unique properties like high level of biocompatibility and its absorption and emission can be tuned with particle size. QDs are an extremely photostable and are considered to be brighter probes as compared to the traditional organic based dye. If the QDs are toxic in nature, it is necessary to surface modify ie, to add or cover some material like a shell over such types of QDs to reduce the toxicity. The non/least-toxic organic based dyes also can be used for cellular imaging application, so that it will cover the toxic QDs to protect the cellular surface and provide good images. Their attractive optical properties promise sensitive cancer imaging properties. In inorganic nanostructures, the ZnS QD is one of the less toxic material and several works are carried using ZnS capped with CdSe QDs for reducing the toxicity. This chapter deals with the cellular/bioimaging applications of the semiconductor QDs.

This chapter introduces recent research on intermediate band solar cells (IBSCs) using quantum dots (QDs). A detailed discussion is given of the numerical analysis of device characteristics based on a self-consistent drift-diffusion model, for which the carrier dynamics, with a particular emphasis on the two-step inter-sub-band photo-absorption (TSPA), and recombination processes are taken into consideration. The current status of the fabrication and performance of high-density In(Ga)As QD solar cells grown using self-organised epitaxy is discussed. Further, maximising TSPA processes via QDs is of paramount importance in a successful implementation of high-efficiency IBSCs and Fourier transform infrared photocurrent spectroscopy provides a powerful tool to study the IR photocurrent response via TSPA in In(Ga)As QDSCs.

In the present paper, the collective near-field effects in a two-graphene sheets plasmonic waveguide loaded with an array of Ag$_2$Se quantum dots excited by external radiation are theoretically studied. This research aims to develop a theoretical approach to realizing controllable excitation and the propagation of surface plasmon polaritons (SPPs) in planar graphene waveguides. The proposed model is based on the semiclassical description that implies the dispersion equation's solution for SPPs excited in two coupled graphene sheets and the embedded quantum dots' energy spectra analysis. Using the finite difference time domain method, the different near-field patterns realized in the waveguides depending on the quantum dots' ordering and an external voltage applied independently to each graphene sheet with additional gold electrodes are numerically investigated. The research shows that applying external voltages allows locally changing the graphene chemical potential, thereby leading to controllable excitation of SPPs in the space between the electrodes. Under these conditions, the propagation direction of the excited SPPs is determined by the geometrical configurations of the gold electrodes providing the required SPP routing. The investigated system offers new opportunities for near-field energy transport and concentration, which can be applied to develop ultra-compact photonic devices.

We describe and present experimental evidence for a mechanism by which photon- assisted polarization current in a semiconductor quantum dot array can produce strong, pulsed THz emission, all at room temperature. Both THz power and waveform are measured and characterized.

Semiconductor quantum dot emits photons that are squeezed below the fundamental noise limit.

Controlling the in-plane symmetry of wide-bandgap semiconductor quantum dots (QDs) is essential for room temperature quantum photonic applications using polarization entangled photon pairs. Herein, we report the formation of 3-fold symmetric group III-nitride QDs at the apex of a triangular pyramid via a self-limited growth mechanism. We employed the in-plane rotational symmetry of the

Long-distance fiber-based quantum communication relies on efficient non-classical light sources operating at telecommunication wavelengths. Semiconductor quantum dots are promising candidates for on-demand generation of single photons and entangled photon pairs for such applications. However, their brightness is strongly limited due to total internal reflection at the semiconductor/vacuum interface. Here we overcome this limitation using a dielectric antenna structure. The non-classical light source consists of a gallium phosphide solid immersion lens in combination with a quantum dot nanomembrane emitting single photons in the telecom O-band. With this device, the photon extraction is strongly increased in a broad spectral range. A brightness of 17 % (numerical aperture of 0.6) is obtained experimentally, with a single photon purity of g ( 2 ) ( 0 ) = 0.049 ± 0.02 at saturation power. This brings the practical implementation of quantum communication networks one step closer.

This work was supported by the National Natural Science Foundation of China (Grants No. 11575174, No. 11674308, No. 11704424, and No. 11774326), the Chinese Academy of Sciences, and the National Key Research and Development Program of China. Photonic graph states are underlying resources for one-way optical quantum computation, quantum error correction, fundamental testing of quantum mechanics, and quantum communication networks. Most existing works, however, are based on the spontaneous parametric down-conversion sources that intrinsically suffer from probabilistic generation and double pair components. Here, we create two important classes of graph states, a polarization-encoded four-photon Greenberger–Horne–Zeilinger (GHZ) state and a linear cluster state, by actively demultiplexing a deterministic single-photon source from a semiconductor quantum dot embedded in a micropillar. A state fidelity of 0.790 ± 0.009 (0.763 ± 0.004) and a count rate of ∼13 Hz are observed for the four-photon GHZ (cluster) state. The results constitute a new route toward the multiphoton entanglement with deterministic single-photon sources. Postprint

Prior research on nanotechnologies in diagnostics, prevention and treatment of coronavirus infections is reviewed. Gold nanoparticles and semiconductor quantum dots in colorimetric and immunochromatographic assays, silica nanoparticles in the polymerase chain reaction and spike protein nanospheres as antigen carriers and adjuvants in vaccine formulations present notable examples in diagnostics and prevention, while uses of nanoparticles in coronavirus infection treatments have been merely sporadic. The current absence of antiviral therapeutics that specifically target human coronaviruses, including SARS-CoV-2, might be largely due to the underuse of nanotechnologies. Elucidating the interface between nanoparticles and coronaviruses is timely, but presents the only route to the rational design of precisely targeted therapeutics for coronavirus infections. Such a fundamental approach is also a viable prophylaxis against future pandemics of this type.

The fabrication of integrated quantum dot (QD)-optical microcavity systems is a requisite step for the realization of a wide range of nanophotonic experiments (and applications) that exploit the ability of QDs to emit nonclassical light, e.g., single photons. Thanks to their ∼20-nm positioning accuracy and to their proven potential for single-photon operation, the QDs obtained by spatially selective hydrogen irradiation of dilute-nitride semiconductors —such as Ga(AsN) and Ga(PN)—are uniquely suited for integration with photonic nanodevices. In the present work, we demonstrate the ability to deterministically integrate single, site-controlled Ga(AsN)/Ga(AsN):H QDs within a photonic crystal (PhC) cavity. The properties of the fabricated QD-PhC cavity systems are then probed by photon correlation—providing clear evidence of single-photon emission—and time-resolved microphotoluminescence spectroscopy. Detailed information on the dynamics of our integrated nanodevices can be inferred by comparing these experiments to the solutions of a rate-equations system, developed by taking into account all the main processes leading to the capture, relaxation, and recombination of carriers in and out of the QD. This allows us to follow the evolution of the relevant recombination rates in our system for varying energy detuning, \(\Delta\)E, between the QD and the PhC cavity. When the QD exciton transition is nearly resonant with the cavity mode, a large (>tenfold) enhancement of the spontaneous emission rate is observed, in substantial agreement with Jaynes-Cummings (JC) theory. For intermediate detunings ( \(\Delta\)E ∼ 1.5–3.5 meV), on the other hand, the observed enhancement is significantly larger than that predicted by JC theory, due to the important role played by acoustic phonons in mediating the QD-PhC cavity coupling in a solid-state environment. Apart from its fundamental interest, the observation of such phonon-mediated, broadband enhancement of light-matter interaction significantly relaxes the requirements for the realization of a large variety of cavity QED-based experiments and applications. These include many photonic devices for which the use of site-controlled Ga(AsN)/Ga(AsN):H QDs would be inherently advantageous, such as those based on the coupling between more than one QD and a single cavity mode (e.g., few-QD nanolasers and QD solids).

Great prospects of using chiral molecules made of semiconductor quantum dots (QDs) as readjustable elements of optically active materials and devices offer them as a potential material base for chi...

In this review we present new concepts and recent progress in the application of semiconductor quantum dots (QD) as labels in two important areas of biology, bioimaging and biosensing. We analyze the biologically relevant properties of QDs focusing on the following topics: QD surface treatment and stability, labeling of cellular structures and receptors with QDs, incorporation of QDs in living cells, cytotoxicity of QDs and influence of the biological environment on the biological and optical properties of QDs. Initially, we consider utilization of QDs as agents in high-resolution bioimaging techniques that can provide information at the molecular levels. The diverse range of modern live-cell QD-based imaging techniques with resolution far beyond the diffraction limit of light is examined. In each technique, we discuss the pros and cons of QD use and deliberate how QDs can be further engineered to facilitate their application in the respective imaging techniques and to produce significant improvements in resolution. Then we review QD-based point-of-care bioassays, bioprobes, and biosensors designed in different formats ranging from analytic biochemistry assays and ELISA, to novel point-of-care smartphone integrated QD-based biotests. Here, a wide range of QD-based fluorescence bioassays with optical transduction, elecrochemiluminescence and photoelectrochemical assays are discussed. Finally, this review provides an analysis of the prospects of application of QDs in selected important areas of biology.

This review explain the physico-chemical basis of semiconductor QDs use in various medical parts: from diagnosis, imaging and labelling to therapeutic. In fact, we have focused on the physicochemical properties of these nanoparticles and related medical applications. So we rely more on how the strategy and method, not exactly the target molecule, although some examples are given. Because you can find full information about each of the sections of diagnosis, treatment and imaging in a number of important review articles. In fact, by reading this review, one can understand why and for what reason semiconductor QDs are used in a particular part of biomedical.

We experimentally studied the influence of both impurity density and dangling-bond density on PL emissions from group-IV-semiconductor quantum-dots (IV-QDs) of Si and SiC fabricated by hot-ion implantation technique, to improve the PL intensity (I PL) from IV-QDs embedded in two types of insulators of quartz-glass (QZ) with low impurity density and thermal-oxide (OX) layers. First, we verified the I PL reduction in the IV-QDs in QZ. However, we demonstrated the I PL enhancement of IV-QDs in doped QZ, which is attributable to multiple-level emission owing to acceptor and donor ion implantations into QZ. Secondly, we confirmed the large I PL enhancement of IV-QDs in QZ and OX, owing to forming-gas annealing with H2/N2 mixed gas, which are attributable to the reduction of the dangling-bond density in IV-QDs. Consequently, it is possible to improve the I PL of IV-QDs by increasing impurity density and reducing dangling-bond density.

International audience; At present, fluorescent spectroscopy is a powerful tool that is used in many biology applications. In practice, fluorescent labels based on organic dyes and semiconductor quantum dots are used. It is noteworthy that the semiconductor quantum dots have distinct advantages over organic dyes. At the same time, the efficiency parameters and modes of detection and excitation have not been investigated sufficiently. The results of theoretical study on the optimization of the excitation and detections modes for detecting ultra-small amounts of CdSe/ZnS core/shell semiconductor quantum dots are presented at this paper.

Colloidal semiconductor quantum dots (QDs) have attracted a great attention for their potential applications in optoelectronic devices, such as water splitting, luminescent solar concentrators, and ...

Quantum dots (QDs), with several unique optical and chemical features, are becoming desirable fluorescent tags for the biological applications that require long-term and highly sensitive imaging. Besides, the conjugation of various functional biomolecules to QDs has enabled wide applications of QDs in biological imaging. This review focuses on the following four types of QDs: semiconductor quantum dots (semiconductor QDs), carbon nanodots (CDs), silicon quantum dots (SiQDs), and polymer dots (Pdots), and summarizes the recent advancements of using these QDs in imaging microorganisms including viruses, bacteria, and fungi. We hope that this review will promote the development of new fluorescent QDs for microbial imaging and extend the applications of QD-based imaging techniques in cell biology and beyond.

This article focus on the recent work carried out on hot charge carrier extraction from colloidal quantum dots (QDs). It has been contemplated that the quantum dot based solar cell (QDSC) can reach...

We have investigated the influence of the average radius and its dispersion of the semiconductor quantum dots (QDs) used in luminescent solar concentrators (LSCs) on reabsorption. To minimize the detrimental reabsorption losses in LSCs, six semiconductors used to fabricate QDs with a wide range of their bulk band gap Eg0 have been considered, specifically: CdS (Eg0 = 2.42 eV), CdSe, (Eg0 = 1.67 eV), CdTe (Eg0 = 1.5 eV), InP (Eg0 = 1.27 eV), InAs (Eg0 = 0.355 eV), and PbSe (Eg0 = 0.27 eV). Altering and , we can determine the optimal size for minimal reabsorption. As it was shown, decreasing the semiconductor bulk band gap from 2.42 down to 1.24 eV we can get such optimum QD size that reabsorption reduces even below the combined experimental error in determination of the absorption coefficient and luminescence intensity. Further reduction of the gap Eg0, however, increases reabsorption at any values of r and Δr: for instance, for PbSe-based QDs of 1-nm radius and dispersion of 1%, reabsorption reaches 54%.