Variation of the steady-state optical properties quantum dots (QDs) caused by photoinduced charge transfer is a widely known phenomenon which hinders QD applications requiring long-term stability signal, for example, bioimaging, single-photon sources, molecular tracking, and lasing. Intense light irradiation may provoke photodarkening, when their photoluminescence (PL) yield (QY) reduced, or photobrightening, QY increases PL becomes brighter. In order to understand nature these processes...

Abstract The effect of induced transparency, which is related to photoinduced bleaching photoabsorbers, being intensely studied and has many applications in the field sensing. Along with this classical effect, numerous studies on transparency coupled plasmon–exciton systems, accompanied by formation hybrid states, have been recently published. a new system results various spectral modifications. For example, manifests itself as narrow dip absorption spectrum system. This can be used sensing,...

Reliable control of spontaneous radiation from quantum emitters, such as dots (QDs), is an extremely important problem in science, nanophotonics, and engineering. The QD photoluminescence (PL) may be enhanced near plasmon nanoparticles because excitation field enhancement or the Purcell effect. However, both these effects have their specific limitations. usually accompanied by a decrease PL yield (QY) due to plasmon-induced energy transfer, effect cannot significantly enhance QDs with...

Quantum dot (QD) encoded microbeads are emerging for multiplexed analysis of biological markers. The quantitative encoding prepared with different concentrations QDs colors suffers from resonance energy transfer the fluorescing at shorter wavelengths to longer wavelengths. Here, we used layer-by-layer deposition technique spatially separate several polymer layers so that distance between them would be larger than Förster radius. We performed fluorescence lifetime measurements investigate and...

Energy transfer from nanostructures to biological supramolecular photosystems is an important fundamental issue related the possible influence of nanoobjects on functions. We demonstrate here two-photon-induced Förster resonance energy (FRET) fluorescent CdSe/ZnS quantum dots (QDs) photosensitive protein bacteriorhodopsin (bR) in a QD–bR hybrid material. The two-photon absorption cross section QDs has been found be about two orders magnitude larger than that bR. Therefore, highly selective...

Semiconductor quantum dots (QDs) are known for their ability to exhibit multiphoton emission caused by recombination of biexcitons (BX). However, the yield (QY) BX is low due fast Auger process. Plasmonic nanoparticles (PNPs) provide an attractive opportunity accelerate radiative recombination. Here, we demonstrate PNPs induced distance-controlled enhancement single QDs. Studying same QD before and after its integration with PNPs, observed a plasmon-mediated increase in QY emission....

The field of quantum technology has been rapidly expanding in the past decades, yielding numerous applications, such as information, communication, and cybersecurity. At core these applications lies emitter (QE), a precisely controllable generator either single photons or photon pairs. Semiconductor QEs, perovskite nanocrystals semiconductor dots, have shown much promise emitters pure photons, with potential for generating pairs when hybridized plasmonic nanocavities. In this study, we...

Conventional approaches to the determination of two-photon absorption cross-section (TPACS) fluorescent semiconductor nanocrystals, including quantum dots (QDs) and nanoplatelets (NPLs), cannot be applied samples with unknown concentrations low optical densities may inaccurate in case multiexciton nanocrystal excitation. Here, we have studied two-photon-excited photoluminescence saturation QD NPL propose a novel technique for determining their TPACS from parameters this process. The allows...

Remote control of the pH medium is an important task for many applications in chemistry, medicine, and biology. using light intelligent cost-effective approach. The nanoscale plasmon–exciton (plexciton) light–matter coupling a physical phenomenon that provokes strong changes optical properties original plasmon exciton bands, resulting transparency dip initial spectrum formation two hybrid plexciton side bands separated by Rabi splitting energy. strength unaffected temperature irradiation...

Changes of optical properties the solutions CdSe/ZnS quantum dots (QDs) covered with trioctylphosphine oxide (TOPO) ligands under pulsed ultraviolet (UV) laser irradiation are observed. The fluorescence yield (QY) QDs decreases by more than an order magnitude when radiation dose approaches 2 × 10^-15J per particle. This process is accompanied a blue shift both and first excitonic absorption peaks. quenching becomes less pronounced overall TOPO content in solution increased. When...

Abstract 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 not easily accessible with other luminophores. We demonstrate here the potential of QDs made from II/VI semiconductors several 10 ns expand lifetime range organic luminophores in...

State-of-the-art research related to increasing the efficiency and reducing cost of solar energy converters is analyzed. An approach solving these issues introduce graphene its derivatives into photoactive layer cells. These materials have record high charge carrier mobility at normal temperatures low absorption cross-sections radiation. The review considers chemical science methods nanotechnology approaches design 2D hybrid structures based on quantum dots. Examples their most successful...

Abstract Efficient biexciton (BX) photoluminescence (PL) from quantum dots (QDs) paves the way to generation of entangled photons and related applications. However, yield (QY) BX PL is much lower than that for single excitons (EX) due efficient Auger‐like recombination. In vicinity plasmon nanoparticles, recombination rates EX may be affected by Purcell effect, fluorescence quenching, excitation rate enhancement. Here, effect resonance spectral position on experimentally studied in two...

The layer-by-layer (LbL) deposition approach allows combined incorporation of fluorescent, magnetic, and plasmonic nanoparticles into the shell polyelectrolyte microcapsules to obtain stimulus-responsive systems whose imaging drug release functions can be triggered by external stimuli. use fluorescent quantum dots (QDs) magnetic (MNPs) yields magnetic-field-driven tools that tracked imaged even deep in tissue when appropriate type QDs wavelength their excitation are used. excellent photonic...

The effective two-photon absorption in the hybrid material comprising quantum dots (QDs) a poly(methyl methacrylate) (PMMA) matrix and gold nanorods (GNRs) was increased 12-fold due to nonlinear energy transfer from GNR plasmons QD excitons.

Abstract The Nobel Prizes in Physics (2022) and Chemistry (2023) heralded the recognition of quantum information science synthesis dots (QDs), respectively. This acknowledgment has propelled colloidal QDs perovskite nanocrystals to forefront technologies. Their distinct emission properties, facilitating efficient generation both single photons photon pairs, render them particularly captivating. Moreover, their adaptability diverse structures, ranging from traditional electronics...

A method for targeted variation of the radiation properties quantum dots (QDs) to control efficiency resonance energy transfer in nanocrystal assemblies and nano-bio hybrid materials has been developed. The is based on strong ultraviolet (UV) laser irradiation QDs allows extinction luminescence spectra be controlled yield decay kinetics varied. Water-soluble have synthesized used analyzing effect from semiconductor nanocrystals photocycle photosensitive protein bacteriorhodopsin (bR) bR–QD...

Hybridized plexcitonic states have unique properties which been widely studied in recent decades many research fields targeted at both fundamental science and innovative applications. However, to make these applications come true one needs ensure the stabilization preservation of electronic optical transitions hybrid nanostructures, especially under influence external stressors, regimes, that not yet comprehensively investigated. The present work shows nanohybrid system, composed plasmonic...

The coherence length of the Frenkel excitons (Ncoh) is one most critical parameters governing many key features supramolecular J-aggregates. Determining experimentally value Ncoh a nontrivial task since it sensitive to technique/method applied, causing discrepancies in literature data even for same chemical compound and aggregation conditions. By using combination different experimental techniques including UV-vis-NIR, fluorescence emission, time-resolved photoluminescence, transient...

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It has been demonstrated that photo-induced changes in the optical properties of semiconductor quantum dots (QDs) can be controlled by tuning parameters their laser irradiation to vary relative contributions photo-brightening and photo-darkening QDs. For this purpose, effects QD size, photon energy, intensity QDs on competing processes have investigated. We found is not accompanied detectable growth photoluminescence (PL) decay time, process being most pronounced for with an originally low...